taxonID	type	description	language	source
03D287B2FFBF362E9AD7FF5A2C3AFE7D.taxon	materials_examined	Type species: Farrea occa Bowerbank, 1862	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFBF36209AD7FE562B7EFDC0.taxon	description	(Figs. 3 & 4, Table 2) Synonymy. Farrea sp. nov. Stone et al., 2011: 18. Material examined. Holotype: USNM # 1196548, ROV ' Jason II' from RV ' Roger Revelle', dive J 2102, 03 August 2004, 26.7 km W of Amatignak Island, Delarof Islands, Amchitka Pass, Aleutian Islands, 51 º 18.549 ' N, 179 º 31.693 ' W, 887 m, partial, dry & ethanol. Description. The holotype consists of 15 fragments, the largest being 35 mm long, of a dichotomously branching tubular stock, with internode length greater than tube diameter, hence appearing spindly for a farreid (Figs. 3 A, B); evidence of anastomosis is lacking in either the in-situ image (Fig. 3 A) or the recovered fragments (Fig. 3 B). Outer tube diameter is 8.5 ± 1.5 (6.9 – 12.7; n = 13) mm; wall thickness is 1.08 ± 0.16 (0.78 – 1.32; n = 10) mm. The color of the preserved fragments is light tan or beige. Both inner and outer surfaces are smooth, without channelization. The skeletal framework is a typical farreoid dictyonal type, with smooth beams. Dictyonalia are mainly formed in a single layer (Fig. 3 C) but in the thicker fragments a second layer may occasionally be added on the dermal side. Meshes are mostly rectangular, elongate in the longitudinal axis, but nearly square meshes are also quite common. Spurs are rough, tapered to a fine point and overwhelmingly curved toward the growth margin, in downstream exhalant water flow (Fig. 3 D), although in some areas they are straight (Fig. 3 C lower). Framework measurements are given at the top of Table 2. Megascleres are pentactins, pileate clavules, and uncinates (dimensions given in Table 2). The pentactins (Fig. 4 A) of dermal and atrial surfaces are regularly cruciate and indistinguishable; all rays are slightly tapered and finely rough (moderately dense microspines); tangential rays are slightly curved towards the body wall (down) and appear in LM to be slightly inflated distally; proximal rays are abruptly tapered at the tip without inflation. A rudiment of the sixth (distal) ray is present. Pileate clavules (Fig. 4 B) occur on both surfaces; their necks are barely swollen; the cap is smooth, bordered by 23 – 25 short, sharp marginal teeth, 3.2 ± 0.6 (2.2 – 4.3; n = 19) µm long. The shaft is entirely covered with short spines inclined away from the head; the proximal tip is not inflated but abruptly tapered to a sharp point. Uncinates are moderate in size but thin (Fig. 4 C); barbs and brackets are well developed in the mid-area and barbs are only moderately inclined from the spicule surface. Microscleres are mainly oxyhexasters and hemioxyhexasters (59 %), discohexasters and hemidiscohexasters (23 %). Oxyhexactins (12 %) and discohexactins (5 %) constitute the less common regular forms (dimensions given in Table 2). Oxyhexasters (Fig. 4 D) and hemioxyhexasters (Fig. 4 E) have short primary rays (1 ° / 2 ° ray length = 0.316). Branched rays have 2 – 3 secondary rays; both primary and secondary rays are tapered to sharp tips and smooth except for short spurs representing undeveloped secondary rays. Discohexasters (Fig. 4 G) and hemidiscohexasters (Fig 4 H) have short primary rays (1 ° / 2 ° ray length = 0.392). Branched rays have 2 – 4 secondary rays; both primary and secondary rays are cylindrical and ornamented with fine reclined spines (Fig. 4 J) although they are sparse on the primary rays. Terminal discs have 4 – 7 marginal spines. Oxyhexactins (Fig. 4 F) and discohexactins (Fig. 4 I) are totally unbranched forms of the oxy- and disco-tipped branched forms. Their rays are similar to those of their branched counterparts in shape and ornamentation, but they are slightly longer in both types. Microscleres with onychoid ray tips are rare (<1 %); they are the size of discohexasters but have thin rays. They are interpreted to be young stages of discohexaster development and not a distinct microsclere category. All fragments are contaminated with spicules of Regadrella okinoseana, collected at the same station, but these are quite easily recognized as foreign in origin. * includes hemioxyhexaster and hemidiscohexaster respectively. Etymology. The species name, aleutiana, reflects the name of its occurrence location, the Aleutian Islands. Remarks. This new Aleutian Islands form of Farrea is unique among the local Alaskan Farrea forms in lacking anchorate clavules. Six forms of Farrea have previously been described as lacking anchorate clavules, but the new form is easily distinguished from each of these. The North Atlantic F. laminaris Topsent, 1904 has an undulatory blade body form and pentactins with macrospines, while the new Aleutian form has a branching tubular body form and microspines on its pentactins. In F. microclavula Tabachnick, 1988, from the Western Pacific Mountains, the major microscleres are disco-tipped (here oxy-tipped), oxyhexasters have longer primary rays (calculated from figures 1 ° / 2 ° ray length = 0.6 vs 0.316 here), discohexactins are absent (present here), and oxyhexactins are only attached to the framework (free here). Unfortunately megasclere dimensions were not provided in the description of F. microclavula, but the qualitative differences noted indicate that the two forms are clearly distinct. The south Australian form assigned to Farrea occa occa by Reiswig, 1992 has no disco-tipped microscleres (28 % here). The form described from off Gibraltar, Atlantic Ocean, by Boury-Esnault et al. (1994) as F. occa, but clearly not assignable to that species, is nearly identical in pattern of spiculation to the new form, but the uncinates are much smaller, mean length 582 µm (2050 µm here); the clavules are much shorter (230 – 270 – 310 µm vs 333 – 411 – 490 µm), and both microsclere classes differ significantly in shape (primary rays longer than terminals in the former but those rays very much shorter in the new form). The New Zealand species, F. anoxyhexastera Reiswig & Kelly, 2011, has no oxyote microscleres (dominant here), and F. ananchorata Reiswig & Kelly, 2011 has two size classes of oxyhexasters (largest with diameter 102 – 216 vs 61.5 – 116.7 µ m here) and discohexasters with long primary rays (1 ° / 2 ° ray length ratio 1.82 vs 0.39 here). Based upon the differences from all known Farrea lacking anchorate clavules, the new Aleutian form is considered here to be a new species, designated as Farrea aleutiana. Review of all video footage collected with the ROV ' Jason II' indicates that this is a rare species, known only from a few locations in Amchitka Pass and near Bobrof Island in the central Aleutian Islands, occurring on small boulders, cobbles, and pebbles at depths between 397 and 1353 m. The skeletons of this and other Farrea spp. provide important substrate for gorgonian corals (Primnoidae and Acanthogorgia sp.).	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFB236279AD7F90A2C51FBF3.taxon	description	(Figs. 5 & 6, Table 3) Synonymy. Farrea kurilensis ssp. nov. Stone et al., 2011: 16. Material examined. Holotype: USNM # 1196549, ROV ' Jason II' from RV ' Roger Revelle', dive J 2099, 31 July 2004, Adak Canyon, 15.9 km SW of Cape Yakak, Adak Island, Aleutian Islands, 51 º 28.091 ' N, 177 º 03.055 ' W, 2105 m, partial, dry & ethanol. Comparative material examined. Farrea kurilensis Okada, 1932, holotype, USNM 22034, USFS ' Albatross', stn 4804, SE of Shimushir Island, Kurile Islands, 24 June 1906, 46 º 42 ' N, 151 º 47 ' E, 419 m; Farrea beringiana Okada, 1932, holotype, USNM 22037, USFS ' Albatross', stn 4790, Cape Monati, Bering Island, Bering Sea, 14 June 1906, 54 º 38 ' 45 " N, 167 º 11 ' 45 " E, 117 m; Farrea kurilensis, BMNH 1938.07.04.119 (from Zoological Institute of the Academy of Sciences, Leningrad), stn 248, Sea of Okhotsk, other data unavailable. Description. The new species holotype consists of over 100 fragments, the largest being 80 mm long, from a stock of very tightly branching and anastomosing tubes, with internode length less than or about the same as tube diameter, hence appearing nearly lettuce-like, with individual tubular components difficult to distinguish (Figs. 5 A, B). Apertures of tube openings on the outer surface are 22 ± 3 (20 – 28; 6) mm; wall thickness is 2.0 ± 0.4 (1.5 – 2.5; 10) mm. The color of the preserved fragments is white. Both inner and outer surfaces are smooth, without channelization (Fig. 5 B). The skeletal framework is a typical farreoid dictyonal type easily seen by naked eye (Fig. 5 C), with smooth beams (Figs. 5 D, E). Dictyonalia are mainly restricted to a single layer but a second layer may occasionally be added on the dermal side. Meshes are mostly rectangular, approximately square, so longitudinal and transverse beam lengths do not differ. Spurs are rough, tapered to a fine point, and usually gently curved downstream (to exhalant flow; Figs. 5 E, F), but in many areas they project directly perpendicular to the plane of the framework without curvature. Framework measurements are given at the top of Table 3. Megascleres are pentactins, regular hexactins, anchorate clavules and uncinates (dimensions given in Table 3). The pentactins (Fig. 6 A) of dermal and atrial surfaces are regularly cruciate and indistinguishable; all rays are straight, slightly tapered, finely rough (moderately dense microspines), and end in abruptly pointed tips. A short rudiment represents an undeveloped sixth (distal) ray; its length is generally less than twice its width and the spicules are here considered to be pentactins. Regular hexactins (Fig. 6 B) occur as parenchymal spicules with rays similar to those of the surface pentactins; they are too rare to provide data for Table 3 but the one figured has rays 227 µm long by 11.2 µm thick. Anchorate clavules (Figs. 6 C – F) occur on both surfaces; their caps have a small central prominence, raised to varying degrees and often with a few coarse spines; the 3 – 10, 23 – 93 µm long marginal spines projecting backwards are rarely straight and more commonly flared outwards or s-shaped. Outer surfaces are mostly smooth, but spines occur across the cap and on the distal spines of some clavules. Darkened surfaces on outer and inner surfaces of some caps (Figs. 6 E – F) appear due to incomplete silicification where the nanospherular silica is seen at higher magnification. The shafts are straight, robust and smooth, ending in blunt parabolic tips without inflation; large shaft spines are absent. Uncinates are of moderate size but thin (Fig. 6 G); barbs and brackets are well developed in the middle and barbs are moderately inclined from the spicule surface. Microscleres consist of only stellate discohexasters of two distinct size and form classes (dimensions given in Table 3). Both are entirely rough and bear terminal discs with 4 – 7 marginal teeth. The smaller, more abundant discohexasters (Fig. 6 I) generally have long primary rays bearing 3 – 7 shorter secondary rays, usually bundled very tightly together, but many are slightly flared at the tips and some flare outwards directly from their insertion on the primary ray. The larger discohexasters (Fig. 6 H) have relatively shorter primary rays that bear 6 – 8 long straight secondary rays. The bases of the secondary rays are fused for a short distance forming a calyx-like base. Most of the discohexasters are easily assigned to these two classes, but a few intermediates occur as verified by a plot of spicule diameter vs 1 º ray length / 2 º ray length (not shown). Etymology. The species name, aspondyla, reflects the absence of spines on the clavule shafts. Remarks: The new Aleutian Islands specimen is clearly closely related to F. kurilensis Okada, 1932 based on the shared characteristic shape of its anchorate clavules as well as the form of its dermal and atrial pentactins. It differs from F. k. forma kurilensis Okada, 1932, as modified by Koltun (1967), in the larger caliber of its tubular body components (22 vs. 10 mm diameter in the latter), lack of pileate clavules, complete absence of shaft spines on its anchorate clavules, absence of oxyhexaster microscleres (the dominant microsclere of the latter), and presence of a large class of discohexasters (absent in the latter). It differs from F. k. forma beringiana, Okada, 1932, as modified by Koltun (1967), in absence of pileate clavules (although these were absent in Okada's original Bering Sea specimen), absence of shaft spines on the anchorate clavules, and presence of a much larger class of discohexasters (91 – 293 vs. 80 – 150 µm diameter in the latter) with calyx-like fusion of the secondary ray bases. Koltun (1967) noted, after examination of seven previously unreported specimens, that F. kurilensis is a polymorphous species but he still maintained distinction between the two forms, now considered subspecies (Reiswig 2002). Other species of Farrea with only anchorate clavules include F. aculeata Schulze, 1899, from Oregon and F. campossinus Lopes et al., 2011 from Brazil; both differ from Farrea aspondyla n. sp. in having their main microsclere as oxyhexasters. The special characters of the new Aleutian Islands form, absence of pileate clavules, absence of shaft spines on anchorate clavules, and presence of a very large class of stellate discohexasters with calyx-like secondary ray bases, are here considered sufficient evidence for genetic isolation and its recognition as a new species, Farrea aspondyla. Review of all video footage collected with the ROV ' Jason II' indicates that this is a common species, locally abundant in some areas and occurring on bedrock, mudstone, boulders, cobbles, and other hexactinellid skeletons at depths between 1887 and 2249 m (likely much shallower but difficult to determine due to presence of conspecifics from which it cannot always be distinguished in situ). When encountered in situ, the majid crab Chionoecetes angulatus was using the sponge as cover; other associated fauna include juvenile crabs (Paralomis and Lithodes spp.). The skeleton of this and other Farrea spp. provide important substrate for gorgonian corals (Primnoidae and Acanthogorgia sp.).	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFB636279AD7FB272BFAF815.taxon	materials_examined	Type species: Pinulasma fistulosum n. sp. Genus diagnosis. Chonelasmatinae of funnel form with hollow tubular fistules covering the lateral body surface, produced by crenulate growth at atrial margin. Fistules open to the atrial cavity but in life closed distally by dense network of unfused spicules; after death fistules also open distally. Primary layer with longitudinally elongate rectangular meshes with transverse-radial connecting beams aligned to form dictyonal lamellae; longitudinal strands present. Thin secondary cortices developed both on dermal and atrial sides with shallow epirhyses but no aporhyses. Dermalia and atrialia are pinular hexactins with proximal rays of greatly varying length. Other megascleres include pentactins, regular hexactins, diactins, tauactins, two classes of scopules, and uncinates. Microscleres are mainly discohexactins and oxyhexactins but a few hemidiscohexasters and hemioxyhexasters also occur. Etymology. The name Pinulasma is here proposed as an arbitrary combination of letters. It is formed to be both euphonious and relatable to the genus Chonelasma, which was presumably formed from “ chone ” = funnel (Gk.) and “ elasma ” = plate (Gk.). The new name is formed to specify pinular dermalia and atrialia as a characteristic of its members. The gender is neuter. Remarks. It is not possible to accommodate the new species described below in any of the presently recognized genera of Chonelasmatinae without seriously modifying the diagnosis of the selected genus. The main incompatibilities are body form and presence and shape of surface pinular hexactins. Among present genera, pinular hexactins occur only in Bathyxiphus Schulze (1899), with a blade-like body, one species of Chonelasma Schulze (1886), C. doederleini Schulze, 1886 with plate-form body, and Tretochone Reid (1958) with ear-like body. In detail shape of the pinular hexactins, those of the new species are markedly unlike those of all the above genera and species.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFB7363A9AD7FF132B3BF9E6.taxon	description	(Figs. 7 – 9, Table 4) Synonymy. " Family Euretidae; Genus nov., sp. nov. " Stone et al., 2011: 19. Material examined. Holotype: USNM # 1196550, ROV ' Jason II' from RV ' Roger Revelle', dive J 2103, 04 August 2004, Amchixtam Chaxsxii, 21.7 km SE of Pochnoi Point, Semisopochnoi Island, Aleutian Islands, 51 º 47.872 ' N, 179 º 57.106 ' E, 1254 m, dry & ethanol; Paratype: USNM # 1196551, same dive and location, 1265 m, dry & ethanol. Description. The overall body form of both specimens is a symmetrical high-aspect funnel; the holotype collected nearly intact, is 29.2 cm tall by 13.7 cm in diameter at the upper end (h / d = 2.14); the paratype, damaged in collection, was in situ, 20.3 cm tall and 13.1 cm in diameter (h / d = 1.55). Both were attached to exposed bedrock by moderate size basal discs at their narrow ends, the holotype on vertical surface and the paratype on horizontal surface; they extend vertically upward, expanding to a round terminal osculum (Figs. 7 A – D). The body wall proper is fairly thin, 2.6 – 3.1 – 4.2 mm (n = 9), and bears small, evenly-distributed hollow fistules projecting perpendicularly from the outer surface. The lumina of the fistules are open to the atrium (Fig. 7 G), and when alive the distal ends of the fistules are closed by dense loose spicule pads (Fig. 7 E) and are thus digitate in form. When loose spicules are lost through death or artificial removal, the remaining skeletal frameworks of fistules are distally open, suggesting to those viewing only dead skeletons that they could be parietal oscula; clearly they do not play that role when alive. In the holotype, the fistules are 7 – 16 – 24 mm tall (n = 18), 6 – 8 – 12 mm in external diameter (n = 33), with the lumen diameter as 3.3 – 4.4 – 6.3 mm (n = 14) at the atrial aperture and 2.5 – 3.2 – 5.1 mm (n = 15) at the distal end (artificially opened). They tend to be distributed in horizontal rows and are spaced more closely horizontally (0.98 mm center to center) than longitudinally (1.4 mm). Many fistules remain as single digitate structures, but about half of them branch distally once or very rarely twice; the plane of branching is not oriented. Where adjacent branches come into contact, fusion of tissues and frameworks occur (Fig. 7 E). The external dermal surface is covered by a fine quadrangular lattice formed by loose pinular hexactins which spans across the underlying inhalant canals (Fig. 7 F). The atrial surface of the main atrium and fistular lumina has similar pinular hexactins but here restricted to the ridges between exhalant canals and not forming a regular quadrangular lattice; the canal apertures are uncovered (Fig. 7 H). The parenchymal skeletal framework of the main funnel wall is typically chonelasmatid in form, consisting mainly of a primary framework of elongate rectangular prismatic meshes, the long sides made by longitudinal strands (beam data given at the top of Table 4). End beams of the meshes are short and tend to be radially ranked, forming vertical septa (Figs. 8 A – E), but not otherwise aligned. Thin cortical layers only one or two meshes in thickness, are appended to both surfaces of the primary framework; these lack longitudinal strands and instead have randomly oriented beams forming triangular meshes. Very shallow round epirhyses are formed in the dermal cortex (Fig. 8 F) but aporhyses are not present in the thin atrial cortex (Fig. 8 G). Longitudinal strands of the main body wall curve smoothly up and out into the framework of the fistules, retaining prismatic mesh form and ranking of the radial end beams (Fig. 8 B). The thin cortical layers also extend smoothly out onto the surface frameworks of the fistules, but epirhyses are not formed in those surfaces. Most beams of the skeletal framework are smooth but some areas are sparsely ornamented by low rounded tubercles (Fig. 8 H). Nodes are not swollen; spurs are long, rough and sharply pointed. Megascleres are pinular hexactins, pentactins, regular hexactins, discoscopules, tyloscopules, tauactins, diactins and uncinates (dimensions given in Table 4). Pinular hexactins (Fig. 9 A) cover both dermal and atrial surfaces of the main body funnel and fistules. They vary greatly in size and shape but all have a relatively long pinulus covered on its distal half by strong sharp obliquely-projecting thorns; the tangential and proximal rays are generally shorter than the pinular ray, straight, smooth, and cylindrical, bearing small sharp proclined denticles at the abruptly rounded or sharp pointed distal ends. Some hexactins have extremely long proximal rays. Pentactins (Fig. 9 B) occur only in subatrial positions in the walls of both the main funnel and fistules, below the covering pinular hexactins. Tangential and proximal rays are straight, cylindrical and mostly smooth, bearing perpendicular and proclined spines at the distal abruptly rounded or pointed ends. A small knob occurs as a rudiment of the sixth distal ray. Regular hexactins (Fig. 9 C) occur in subdermal and subatrial positions on both the main funnel and fistules; their rays are similar to those of the pentactins. Discoscopules (Fig. 9 D) occur almost globally, echinating both dermal and atrial surfaces, as canalaria and as parenchymal spicules without association with surfaces. The neck is generally abruptly inflated from the shaft, often with four swellings, and carries 1 – 8, mostly 4 – 5, thin, straight or slightly out-curved tines ending in very small marginally toothed discs. The shaft tapers smoothly to a very sharp tip. All surfaces are finely spined but in a few the main part of the shaft appears smooth in SEM. Tyloscopules (Fig. 9 E), over twice as large as the discoscopules, occur only echinating the highly restricted atrial surface of the fistules. The neck tapers smoothly from the shaft, without abrupt inflation; the 3 – 4 – 6 tines are straight, robust, and each ends in a swollen marginally-toothed cap that is not distinctly wider than the upper end of the tine shaft. They are also entirely rough and have a shaft tapering to a very finely pointed tip. Tauactins (Fig. 9 F) occur only in the felt cover of spicules occluding the outer tips of the fistules. Their centrum bears three small knobs as rudiments of undeveloped rays. The three developed rays are straight, finely and sparsely spined, gradually tapering to more roughened distal parts ending in abruptly rounded or sharp tips. Diactins (Fig. 9 G) occur only in a subatrial position of main funnel and fistule walls where they lie tangential to the surface. Their centrum bears four knobs as rudiments of undeveloped rays; the two developed rays are similar to those of the tauactins. Uncinates (Fig. 9 H) echinate all surfaces of both the main funnel and fistules where they project vertically and obliquely beyond the pinular hexactins. They have well developed brackets and barbs, the latter of which extend parallel to the spicule surface, projecting very slightly at their tips. The tight feltwork of loose spicules covering the outer ends of the fistules consists of pinular hexactins with long proximal rays, hexactins, discoscopules, tauactins, diactins and uncinates; pentactins, tyloscopules and microscleres are absent from these structures. Microscleres consist of discohexactins (75 %), hemidiscohexasters (4 %), oxyhexactins (20 %) and hemioxyhexasters (<1 %) (dimensions given in Table 4). All of these occur throughout the walls of the main funnel and fistules without restricted locations. Discohexactins (Fig. 9 I) have straight rays covered in robust reclined thorns and end in discs with 5 – 8 marginal teeth. Hemidiscohexasters (Fig. 9 J) are similar but have branching of only one or two rays resulting in two or very rarely three secondary rays; the very short primary rays are smooth. Oxyhexactins and hemioxyhexasters (Fig. 9 K) are entirely smooth within the resolution limits of the SEM available. Rare branching of one or two rays results in hemioxyhexasters with short primary rays. Etymology. The species name, fistulosum, refers to the fistules covering the outer surface of the specimens. Remarks. The new species (and monospecific genus) shares the typical chonelasmoid primary layer of elongate prismatic meshes and aligned radial beams (septa) with the genera Chonelasma, Periphragella, Tretochone and Verrucocoeloidea. The main conflicts with placement of the new form within the genus Chonelasma are that all present members are plate- or frond-like in body form, completely lacking tubular projections of the body wall. While most Chonelasma species have surface pentactins, pinular hexactins occur in three species: C. doederleini Schulze, 1886, C. hamatum Schulze 1886, and C. chathamense Reiswig and Kelly, 2011. It remains uncertain if C. doederleini is correctly placed since its body form is poorly known; it may eventually be moved to Pinulasma when better specimens are available. Periphragella has no members with pinular hexactins and the radial tubules are distally open by small parietal oscula, closed during life in the new form. The monospecific genus Tretochone has pinular hexactins in uncertain location but lacks external fistules and has a unique skeletal channel system of amarrarhyses, lacking in the new species. The likewise monospecific genus Verrucocoeloidea agrees with the new species in funnel form and presence of radial tubules, but those tubules are distally open when alive in V. burtoni and it lacks pinular hexactins. These basic differences prevent assignment of the new form to any of the presently known Chonelasmatinae. It is here designated as the only known member of a new genus Pinulasma, and named P. fistulosum. Review of all video footage collected with the ROV ' Jason II' indicates that this is a common species, locally abundant in some areas and occurring singly or in small patches on bedrock, mudstone, boulders, and cobbles at depths between 773 and 2084 m. Juvenile Verrill’s Paralomis crabs (Paralomis verrilli) use the atrium as refuge habitat.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFAB363A9AD7F9DB2CC8F90A.taxon	materials_examined	Type species: Tretodictyum tubulosum Schulze, 1886	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFAB36319AD7F8BD2F82FDE5.taxon	description	(Figs. 10 & 11, Table 5) Synonymy. Tretodictyum sp. nov. Stone et al., 2011: 20. Material examined. Holotype: USNM # 1196552, ROV ' Jason II' from RV ' Roger Revelle', dive J 2104, 05 August 2004, Amchitka Pass, 49.8 km WSW of Gareloi Island, Aleutian Islands, Alaska, 51 º 41.788 ' N, 179 º 35.030 ' W, 866 m, partial, dry & ethanol. Description. The holotype (Fig. 10 A) was a widely flared funnel, 16.8 cm tall, 25.1 x 16.9 cm in major and minor diameters, with a deep notch in one side and attached centrally to an oblique bedrock surface by a short narrow stem and basal disc. Most was recovered and conserved as three main dry fragments (Fig. 10 B) and four smaller fragments in ethanol. The body wall is 5 – 6 mm thick in older parts and 3 mm thick at the growing margin. When tissues are intact, in either wet or dry state, the two surfaces are distinctly different to the naked eye. The outer or dermal side is markedly lineated by a system of longitudinal light ridges and dark grooves with ca 2 mm repeat spacing, radiating from the center (above the short stem) to the growth margin (Fig. 10 C). These subsurface structures are covered by a transparent quadrangular spicule lattice raised above the skeletal frame and thus easily visible (Fig. 10 E) with mesh spacing of 216 – 382 – 547 µm (n = 67). The inner or atrial surface has an opaque feltlike cover of more tightly packed spicules, not raised above the skeletal framework; it is penetrated by round apertures distributed rather evenly without pattern (Fig. 10 D). The openings in dry fragments are sharply defined by the loose spicule feltwork; they are 0.95 – 1.48 – 2.07 mm diameter (n = 50) (Fig. 10 F). Where wet tissues remain intact in the ethanol fragments, margins of the soft tissue appear as white bands extending slightly inside the spicule margins (Fig. 10 G). These visible apertures are clearly the terminal openings of exhalant canals; they are not the skeletal channels, here schizorhyses, although the channels are contained within the canals. When loose spicules are removed the margins of the schizorhyses are much less sharply defined than the water canals. Color of the dried fragments is light brown; fragments in ethanol are white. The skeletal framework, after cleaning, is a typical three-dimensional tretodictyid system of longitudinal septa joined laterally through intervening low-density spaces. At the growing margin the vertical sheets of dense dictyonal framework, septa, undergo bifurcation to maintain even spacing between these elements (Fig. 10 H). Septa are 0.71 – 1.10 – 1.65 mm thick (n = 17) and gaps (grooves) are 0.52 – 0.79 – 1.12 mm wide (n = 14); mean repeat period is 1.89 mm. The lateral dictyonal connectives joining adjacent septa are sparse (Fig. 10 I) and scattered throughout the width of the wall. Indeed, the inner and outer surfaces of the cleaned skeletal framework in the marginal areas cannot be distinguished. The septa (Fig. 10 J) are constructed of longitudinal strands, which in the middle run straight to the growing margin, but on both sides curve smoothly out the dermal and atrial surface to end on those surfaces. There are no specialized cortical layers. Radial beams connecting adjacent longitudinal strands are perpendicular to the strands and are weakly ranked to form curved lines of aligned beams; meshes are rectangular and nodes are not swollen. In older septa in more medial locations, dictyonal elements are inserted so septa become denser. Thin cortical layer development occurs on both surfaces resulting in a stronger framework; the two surfaces can now be distinguished since cortex development is slightly different. On the dermal side the cortex adds thicker lateral strands between septa (Fig. 10 K) while on the atrial side oblique lattice plates circumscribe entrances to the schizorhyses (Fig. 10 L). The channel system of schizorhyses is restricted to the lowdensity gap between septa; channels branch and anastomose within these spaces but there appears no provision for joining channels of adjacent gaps. Beams are ornamented with sharp conical spines throughout the framework, but very small areas may be smooth; nodes are not swollen; spurs are mainly rough, long and sharply pointed, although smooth, short and inflated ones can be easily found. Megascleres are subhexactins to pentactins, regular hexactins, strongyloscopules and uncinates (dimensions given in Table 5). The subhexactins to pentactins (Fig. 11 A) are surface spicules of both dermal and atrial sides. Rays are strongly tapered, uniformly ornamented by moderate spines, and end in blunt or pointed tips (Figs. 11 B, C), often with reduction of diameter in steps. The short rounded distal ray or knob bears large spines projecting obliquely outward; the degree of reduction of the distal ray is variable (Fig. 11 D) but it is never significantly developed. Regular hexactins (Fig. 11 E) are parenchymal in position, and have six nearly equal cylindrical rough rays ending in abruptly pointed tips. Strongyloscopules (Fig. 11 F) occur projecting slightly from both dermal and atrial surfaces. They have a rather sharp inflation at the neck-shaft transition and carry 3 – 4 – 8 strong straight tapering tines ending in discoid caps that are not larger in diameter than the upper tine shaft. In LM they may appear to be slightly tylote but they are clearly not so in SEM. The tines and head are densely covered by small reclined spines; the straight shaft is entirely but sparsely covered in small spines that become larger and more reclined near the sharply pointed tip. Uncinates (Fig. 11 G) project in very tight bundles from all external surfaces. They are relatively large for tretodictyids, but exhibit the typical extremely small brackets and minute barbs that are almost invisible in LM. Microscleres consist of mainly oxyhexasters (93 %) and stellate discohexasters (7 %), with a very few oxyhexactins (<1 %) and onychohexasters (« 1 %); all types are generally distributed. Oxyhexasters (Fig. 11 H) are stout, each short primary ray bearing 2 – 4 widely spread, straight secondary rays that end in rather abruptly pointed tips. They appear entirely smooth in LM but prove to have a very few small reclined spines in SEM. The few oxyhexactins (Fig. 11 J) have the same characters of the oxyhexasters but without ray branching. Discohexasters (Fig. 11 I) are stellate with primary and secondary rays about equal in length. Each primary ray bears 4 – 7 – 10 secondary rays that end in caps, which like the scopules are not significantly larger than the supporting shafts; they could therefore be called strongylohexasters, a new spicule type name. All surfaces bear a dense cover of small reclined spines. The extremely rare onychohexasters (not figured, only two seen) are spherical, each primary bearing 3 – 4 secondary rays ending in a tuft of 3 – 6 slightly reclined marginal claws. Ray length proportions are like the oxyhexasters, but their rays are more heavily spined. Etymology. The species name, amchitkensis, refers to the location of collection, Amchitka Pass. Remarks. The new Aleutian Islands specimen with preponderance of oxyhexasters clearly belongs to the genus Tretodictyum. With its funnel-like body form it is excluded from four tubular species but is possibly related to three plate or cup-form species, T. minor (Dendy & Burton, 1926), T. montereyensis Reiswig et al., 2008, and T. cocosensis Reiswig, 2010. It differs from the Indian Ocean T. minor in having atrialia and possession of a moderate number of discohexasters, both of which are absent in the latter. It differs from the California T. montereyensis in having longer uncinates (846 vs 500 µm) and in presence of discohexasters, which are absent in the latter. It differs from the tropical E Pacific T. cocosensis in the shape of the subhexactin distal ray, the presence of only one class of scopules (two classes in the latter) and in its larger uncinates. These differences verify that the Aleutian Islands specimen is distinct from all presently known members of the genus, and it is here erected as holotype of a new species, T. amchitkensis. Review of all video footage collected with the ROV ' Jason II' indicates that it is uncommon species, locally abundant in some areas, occurring singly on bedrock, mudstone, boulders and cobbles at depths between 704 and 1264 m. Order Lyssacinosida Zittel	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFA036319AD7FD092C18FCCC.taxon	materials_examined	Type species Regadrella phoenix Schmidt, 1870	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFA036329AD7FC052BEFFE57.taxon	description	(Figs. 12 & 13, Table 6) Synonymy: Regadrella okinoseana Ijima, 1896: 250; 1901: 223; Levi & Levi 1982: 292; Reiswig 1992: 33; Stone et al., 2011: 25.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFA036329AD7FC052BEFFE57.taxon	materials_examined	Material examined. USNM # 1196553, ROV ' Jason II' from RV ' Roger Revelle', dive J 2102, 03 August 2004, S Amchitka Pass, 27.4 km W of Amatignak Island, Delarof Islands, Aleutian Islands, Alaska, 51 º 17.469 ' N, 179 º 32.585 ' W, 1386 m, partial specimen, dry & ethanol. Description. The single specimen from the Aleutian Islands is a soft flattened sac with a wide but subdivided oscular aperture (Fig. 12 A); dimensions of the specimen lacking the attachment base (not collected) are 18.8 cm tall, 12.8 cm wide, 9.1 cm thick. The body wall is 3 – 4 mm thick. Prostalia are not present. The characteristic Regadrella surface pattern of pits and ridges with small parietal oscula at the center of pits (Table 6) is developed only on the external body edges that remain free of contact with the surrounding substrate (Figs. 12 B, C). The larger frontal surfaces that contact the substratum lack this pattern but still have parietal oscula scattered irregularly across their surface. Parietal oscula are ovoid with mean major diameter of 2.6 mm (Fig. 12 D). The main oscular edge is curled outward (Fig. 12 A) but a cuff and sieve plate are absent. Within the single oscular margin, the distal atrial cavity is subdivided into four separate passages by tissue bridges joining the atrial wall surfaces. One of these bridges extends longitudinally at least half the length of the body, thereby flattening and subdividing the distal atrial cavity into two main passages. In the lower half of the saccate body, the two longitudinal atrial passages join to form a single open atrial cavity. Before collection, the specimen was attached under the edge of a large mudstone mound with the osculum exposed (Fig. 12 E). Color in life was white; dried and ethanol-preserved samples are light beige. The new location is quite remote from the known distribution of this species (Fig. 12 F). The main supporting skeleton is a network of loose interwoven unfused diactins resulting in a very soft texture in the upper body. In the lower body quarter, internal diactins are haphazardly fused at contact points, resulting in a stiff but still flexible texture in a soft surface in this area. Main dermal hexactins and atrial pentactins remain unfused throughout the body surfaces. Megascleres (spicule dimensions are given in Table 6): Parenchymal megascleres are thick principal diactins and thin intermediate and comital diactins. Thick diactins are slightly curved, smooth, with slight medial swelling and rounded inflated tips (Fig. 13 L). Thin diactins are similar (Fig. 13 K) but have acutely pointed tips. Dermalia are mainly hexactins with a very few subhexactins. The primary hexactins are large sword-shaped forms (Fig. 13 A) with straight, robust tapering rays that end in slightly roughened sharp tips. The distal ray is shorter and the proximal ray is much longer than the tangential rays. Smaller hexactins with all rays nearly equal in length (Figs. 13 B, C) are less abundant. Atrialia are mainly pentactins (Fig. 13 D), with a few subhexactins (Fig. 13 E), hexactins (Fig. 13 F), irregular tetractins, stauractins with two reduced knobs (Fig. 13 G), triactins (Fig. 13 H) and diactins (Fig. 13 I). All atralia have smooth rays that end in slightly rough rounded tips. Parietal oscular membranes have most types of atrialia, but also small stubby hexactins and pentactins and very small distinctive diactins with four central knobs (Fig. 13 J) found nowhere else. Microscleres consist mainly of floricomes, oxystaurasters, and graphiocomes, but oxyhexasters, oxystauractins, and oxydiasters occur in small numbers. Floricomes (Fig. 13 M) have short smooth primary rays ending in small discs; 7 – 15 s-shaped terminals originate from each primary disc in a single marginal whorl and together form a perianth. Internal (within perianth) surfaces of the terminals are smooth but the outer surfaces bear a continuous band of small spines extending up under the 2 – 4 large claws on the outer margin of the terminal swelling. Oxystauractins (Fig. 13 N) are sturdy microscleres with only four nearly smooth, crucial, primary rays, each of which supports 2 – 5 longer terminal rays ornamented with reclined spines (Fig. 13 P). Oxyhexasters (Fig. 13 O) are similar to the staurasters, but bear the full set of six primary rays, each of which carry 3 – 6 straight or slightly curved rough terminal rays. Graphiocome centers (Fig. 13 Q) have short, strong, nearly smooth primary rays, each of which ends in a small furry disc entirely covered by the ca 120 short bases of the invariably broken off terminal rays; articulation facets are only 0.2 µm in diameter. The loose terminal rays (Fig. 13 R) are slightly sinuous (perhaps spiralled?) with an articulation base bearing a facet and two teeth; the raphidial ray is completely but sparsely ornamented with small spines, basally proclined and distally reclined. These spicules must be truly spectacular when they are intact. Remarks. Although the body form of the Aleutian Islands specimen differs in many respects from a typical Regadrella okinoseana, its spiculation agrees entirely with that species. The site of collection of the new specimen is ca 3700 km distant from the nearest reported occurrence of R. okinoseana in Japan, and thus represents a very striking range extension (Fig. 12 F). Review of all video footage collected with the ROV ' Jason II' indicates that it is an uncommon species occurring singly on mudstone, bedrock and possibly hexactinellid skeletons at depths between 1071 and 1395 m.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFA436359AD7FF5A2C0BFD04.taxon	discussion	Remarks. The above change in diagnosis of the subfamily Rossellinae is required by reinstatement of the subfamily Acanthascinae as proposed below. Genus Aulosaccus Ijima Type species: Aulosaccus schulzei Ijima, 1896	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFA436099AD7FCCD2F61FEE7.taxon	description	(Figs. 14 & 15, Table 7) Synonymy. Aulosaccus schulzei Ijima, 1896: 252; 1898: 51; 1904: 110; Koltun 1967: 68; Tabachnick 2002: 1447; Lee et al. 2007: K 257; Stone et al. 2011: 33.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FFA436099AD7FCCD2F61FEE7.taxon	materials_examined	Material examined. USNM # 1196554, ROV ' Jason II' from RV ' Roger Revelle', dive J 2105, 06 August 2004, 4.5 km W of Cape Sajaka, Tanaga Island, Aleutian Islands, Alaska, 51 º 52.021 ' N, 178 º 17.720 ' W, 1320 m, 1 partial specimen attached to cobble, dry & ethanol. Comparative material examined. A. schulzei holotype, MCZ 10004, Sagami Bay, Japan, prior to 1896, dry. A. albatrossi holotype, USNM 22111, USFS ' Albatross' stn 4797, 20 June 1906, Staritschkof Island off South Kamchatka Peninsula, 52 ˚ 37.8 ' N, 158 ˚ 49.8 ' E, 1248 m, ethanol Description. The collected fragment is the top quarter of a slightly flattened sac, 53 cm long by 25 cm diameter, with large flared oscular margin (Figs. 14 A, B); dimensions of the fragment (Fig. 14 C) are 135 mm tall, 110 mm wide, and 34 mm in wall thickness in the middle. All surfaces are smooth, without prostalia, veil, or conules. The oscular margin is thin and without marginalia. The dermal surface has visible strands of hypodermal pentactins and diactins, oriented in all directions, forming a subsurface network supporting the dermal spicule lattice and obscuring the apertures of the subdermal inhalant canals (Figs. 14 C, D). The dermal lattice (Figs. 14 D, E) is a rectangular meshwork with mean side length of 122 µm, composed of about equal numbers of hexactins, pentactins, and stauractins. The atrial surface has openings of exhalant canals generally visible through the less regularly organized atrial lattice (Fig. 14 F). Meshes of the atrial lattice, composed mainly of hexactins with a few stauractins and pentactins, are not rectangular and microscleres, not present in the dermal lattice, make up a significant component of this structure. The main supporting skeleton is a network of loose interwoven unfused diactins occurring in bundles or singly and oriented without order. Spicule fusion probably occurs only in the basidictyonal skeleton, not collected. Within the moderately firm surface layers, the main parenchyma is cavernous, resulting in a very soft overall body texture. Color of the fresh specimen was white; when preserved in ethanol or dried it is light brown. Megascleres: (spicule dimensions are given in Table 7). Hypodermal pentactins (Fig. 15 A), and a very few triactins and irregular tetractins, are mostly crucial, rarely semi-paratropal, and smooth, with long tapered rays ending in rough sharp tips. Their tangential rays are bundled with thick and thin diactins to form primary support for hexactine dermalia. Dermalia (Fig. 15 B) are entirely rough spicules with cylindric rays ending in rounded and sometimes inflated tips; 37 % are hexactins, 31 % pentactins, and 32 % stauractins. Hexactins are distributed mainly over the hypodermal strands, pentactins at edges of strands, and stauractins over the unsupported middle of the larger lattice fields. Atrialia are composed of the same three spicule types (Fig. 15 C), but they are larger than dermalia, tend to have elongate proximal rays in pentactins and one axis elongate in hexactins. Parenchymal megascleres are all diactins, including thick principal diactins (Fig. 15 D) and thin intermediate and comital diactins (Fig. 15 E). Thick principal diactins are slightly curved, generally smooth, with no medial swelling and rough rounded or parabolic tips. Thin diactins are straight to sinuous, generally smooth with a significant medial swelling and rough parabolic tips. Short straight diactins (Fig. 15 F) are associated with only the atrial surfaces. µm unless otherwise indicated). Microscleres consist of immense discasters, also known as solasters, hemioxyhexasters, oxyhexactins and variants, and microdiscohexasters. The subdermal solasters (Fig. 15 G) are derived discohexasters with centrum expanded to a solid sphere, entirely enclosing the primary rays. Terminal rays emanating directly from the centrum are unequal in length, ornamented with short reclined barbs, and end in marginally toothed discs. Oxy-tipped microscleres (Fig. 15 H) are very thin and mainly associated with the atrial skeleton; they include regular oxyhexactins, hemioxyhexasters and an array of forms with reduced ray numbers — 2, 3, 4, 5 developed rays — but never complete oxyhexasters. They are all rough, all terminal rays ornamented with reclined spines. Many have sharp bends at the end of the primary rays, with one or two developed rays and a short spur emanating from that point; compact spiral variants are rare. Microdiscohexasters (Fig. 15 I) are very rare and associated with both surface skeletons. They have short, thick, smooth primary rays, each of which supports 5 – 10 spined, irregularly sinuous terminal rays ending in very small discs with recurved marginal teeth. Remarks. This species is widely distributed in the N Pacific, from Sagami Bay, Japan through the Kurile Islands and the Okhotsk Sea (Tabachnick, 2002) and has recently been reported from Central California (Lee et al. 2007). Our discovery of A. schulzei in Alaska is not surprising, but it represents a considerable range extension of ca 2,000 km from its nearest previously reported occurrence in the Okhotsk Sea. The new Aleutian Islands specimen agrees in virtually all details with the holotype specimen from Sagami Bay, Japan. In reviewing other possible assignments of this specimen, we discovered that there are no significant differences between A. albatrossi Okada, 1932 from off S Kamchatka Peninsula, and A. schulzei. In his description of A. albatrossi, Okada described its macrodiscohexasters (not figured) as 250 – 650 µm in diameter (we found 409 – 592 – 788 µm, n = 8, in the holotype), terminal rays as smooth with conically convex discs (we found terminal rays rough with hemispheric discs), and two size classes of microdiscohexasters of 32 – 40 and 50 – 56 µm diameters (we found one class, 23 – 34 – 42 µm, n = 127). Okada's description of A. albatrossi is, like many of his other descriptions, clearly unreliable and almost all reputed differences between the species evaporate when the holotypes are directly compared. Maximum size of macrodiscohexasters (solasters) is quite variable between specimens of the same species and is not alone considered a sufficient basis for distinguishing between species. We thus propose A. albatrossi Okada to be recognized as a junior synonym of A. schulzei Ijima. The description here of the Aleutian Islands specimen is the first documentation of A. schulzei spicule forms with SEM. Review of all video footage collected with the ROV ' Jason II' indicates that it is a rare species occurring singly on bedrock, boulders, and cobbles at depths between 1270 and 1350 m. Associated fauna include juvenile lithodid crabs (Paralomis verrilli and Lithodes couesi), pandalid shrimps, and the large ophiuroid Gorgonocephalus eucnemis.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF98360A9AD7FEEB2CF9F95D.taxon	description	(Figs. 16 & 17, Table 8) Synonymy. Calycosaccus ijimai, Schulze, 1899: 30.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF98360A9AD7FEEB2CF9F95D.taxon	materials_examined	Material examined. USNM # 1196555, ROV ' Jason II' from RV ' Roger Revelle', dive J 2095, 26 July 2004, 25.4 km SSW of Amlia Island, Aleutian Islands, Alaska, 51 º 48.693 ' N, 173 º 49.965 ' W, 843 m, whole specimen attached to a boulder was collected in pieces, dry & ethanol. Comparative material examined. Calycosaccus ijimai holotype, USNM 07529, USFS ' Albatross', stn 2853, 09 August 1888, SW of Kodiak Is, Alaska, 56 ˚ 00 ' N, 154 ˚ 19.5 ' W, 291 m. Aulosaccus pinularis holotype, USNM 22112, USFS ' Albatross', stn 4790, 14 June 1906, Bering Sea, 54 º 39 ' N, 167 º 12 ' W, 117 m. Description. The specimen encountered in situ (Fig. 16 A) is a tubular sac flattened on one side at contact with an inclined substrate, with a single large osculum opening opposite the flattened side but subterminal in position. About one half of the body was recovered as a piece 15 cm long by 9.5 cm wide, by 8 – 13 mm thick. This was subdivided into three smaller 3 x 6 cm subsamples preserved in 95 % ethanol and one large dry fragment 14.5 x 6.7 cm (Fig. 16 B). Both internal and external surfaces are smooth, without prostalia, hyperdermal veil or conules. The oscular margin is sharp, thin and without marginalia. The dermal layer is sturdy and easily detachable from the rest of the body wall; it is supported by clearly visible strands of hypodermal diactins oriented in all directions, forming a subsurface network supporting the dermal spicule rectangular lattice (Figs. 16 C, D). The dermal lattice has such fine mesh (143 ± 26 µm sides) that it visually obscures the underlying apertures of the subdermal inhalant canals in the dried fragment (Fig. 16 B). The atrial surface has a more irregular lattice with larger and more irregularly shaped mesh openings. This lattice overlies (covers) the apertures of the exhalant canals, which are generally visible through the atrial lattice (Figs. 16 E, F). Both dermal and atrial lattices are composed exclusively of pinular hexactins. The main supporting skeleton is a network of loose interwoven unfused diactins, occurring singly or in bundles, oriented without order. Spicule fusion probably occurs only in the basidictyonal skeleton, not collected. Within the moderately firm surface layers, the main parenchyma is cavernous, resulting in a very soft overall body texture. The spacious atrial cavity does not project into the short stalk. Color of the fresh specimen is white; when preserved in ethanol or dried it is light brown. Megascleres: (spicule dimensions are given in Table 8). Hypodermal pentactins are absent in this species. Dermalia (Fig. 17 A) are pinular hexactins with moderate bushy pinular ray; the 5 non-pinular rays are all smooth over the proximal half and roughly spined on the distal half. Atrialia (Fig. 17 B) are all similarly pinular hexactins but all rays are longer and the pinulus is narrower and less bushy than the dermal pinules. Neither pentactins nor stauractins were found as dermalia or atrialia. Hypodermal and parenchymal megascleres are all diactins, including thick principal diactins and thin hypodermal, intermediate and comital diactins. Thick principal diactins are slightly curved, generally smooth, with no medial swelling and rough rounded or parabolic tips (not figured). Thin diactins (Fig. 17 C) are straight to sinuous, generally smooth with a significant medial swelling and rough parabolic tips. Microscleres consist of immense discohexasters, also known as solasters, oxyhexasters, oxyhexactins and microdiscohexasters. The subdermal solasters (Fig. 17 D) have 6 readily detected, swollen but separate primary rays (Fig. 17 E); the degree of separation seen in these is strongly dependent upon orientation of the visualized spicule. Terminal rays emanating directly from the primary lobes are unequal in length, ornamented with short reclined barbs, and end in marginally toothed discs (Fig. 17 F). Oxy-tipped microscleres are moderately robust (normal thickness) oxyhexasters (Fig. 17 G) with 2 – 3 terminals per primary ray, regular oxyhexactins (Fig. 17 H), and hemioxyhexasters. They appear smooth in LM but are finely rough in SEM (Fig. 17 I). Microdiscohexasters (Fig. 17 J) are common and associated with sub-surface skeletons of both surfaces. They have short, thick, smooth primary rays, each of which supports 6 – 20 rough crooked terminal rays that end in very small discs with recurved marginal teeth. Remarks. The main distinctions between Aulosaccus schulzei and A. ijimai are that the former species has pentactin hypodermalia and pentactins as the most abundant dermalia and atrialia while the later has diactins as hypodermalia and pinular hexactins as dermalia and atrialia. They are clearly different species. The Aleutian specimen described here agrees with Schulze's (1899) description of Calycosaccus ijimai (later moved to Aulosaccus) in all general features, but the dermalia and atrialia are slightly larger, and the microdiscohexasters are slightly smaller than the informal approximate sizes given by Schulze. Significantly, this is only the second specimen of A. ijimai ever reported, and lies 1,360 km WSW of the type location of Schulze's specimen south of Kodiak Island in the Gulf of Alaska. The present report also includes the first and only objective spicule data set and SEM figures of spicules of this species. The new Aleutian specimen, however, does not differ significantly from the type description of A. pinularis Okada, 1932 from the Commander Islands at the eastern end of the Aleutian chain, nor from Koltun's (1967) description of an additional specimen assigned to that species from Paramushir Island at the tip of the Kamtschaka Peninsula. Okada provided no figures of the type specimen nor of its spiculation. The only data given by both Okada and Koltun are informal typical spicule sizes, like those given by Schulze (1899). In our re-examination of the holotype of A. pinularis, we found the length of the atrialia pinular ray to be 188 ± 30 (95 – 249, n = 62) µm, completely outside the range of 260 – 300 µm given by Okada and parroted by Koltun. For comparison, we obtained new data for the same measurement from Schulze's type specimen of C. ijimai to be 152 ± 37 (79 – 269, n = 100) µm, slightly smaller in mean length than Okada's specimen, but covering a similar range. The major difference between the two species descriptions is the degree of pinularity of the surface hexactins, a subjective evaluation made by the two different original authors that is difficult to accept as significant. Our re-examinations of the type material have convinced us that these are both the same species and A. pinularis Okada is here moved to junior synonym of A. ijimai Schulze. Review of all video footage collected with the ROV ' Jason II' indicates that this is a rare species occurring singly on bedrock, mudstone, and boulders at depths between 843 and 1715 m. µm unless otherwise indicated). Genus Bathydorus Schulze Type species: Bathydorus fimbriatus Schulze, 1886	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF9E36039AD7FE082D27FD7F.taxon	description	(Figs. 19 & 20, Table 10) Synonymy. Caulophacus (Caulophacus) sp. nov. Stone et al., 2011: 35. Material examined. Holotype: USNM # 1196557, ROV ' Jason II' from RV ' Roger Revelle', dive J 2100, 01 August 2004, Adak Canyon, 13 km SE of Cape Yakak, Adak Island, Aleutian Islands, Alaska, 51 º 31.531 ' N, 177 º 05.417 ' W, 1806 m, dry & ethanol. Other material. C. (C.) aff. adakensis, USNM # 1196558, ROV ' Jason II' from RV ' Roger Revelle', dive J 2096, 28 Jul 2004, North Aleutian Slope, 32.8 km N of Atka Island, Aleutian Islands, Alaska, 52 º 23.570 ' N, 174 º 53.077 ' W, 2180 m, long dead, dry. Description. The truly magnificent holotype (Figs. 19 A, B), an extremely large mushroom-shaped body borne on a long rigid stalk, was collected intact but the stalk was intentionally broken for storage and shipping. Total length of the dried specimen, with body canted unnaturally on stem during drying, is 90.3 cm; in natural state the length was 75 cm. The body disc (dry) is 31 x 40 cm in diameter and up to 38.5 mm in thickness. Both lower (= inhalant or dermal) (Fig. 19 C) and upper (= exhalant or atrial) (Fig. 19 D) surfaces are smooth, lacking prostalia, with loose spicule lattices covering the subsurface canal entrances, 3 – 5 mm in diameter in the lower surface and 5 – 8 mm in diameter in the upper surface, easily visible through the covers. A horizontally extensive subsurface space underlies the covering lattice in the inhalant area, but this is lacking in the exhalant area; there the exhalant canals run directly to the covering lattice without an intervening subsurface cavity. The 68 cm long stalk tapers from its insertion on the lower body surface to a diameter of 2.1 cm at midpoint and 1.8 cm at its minimum just above the large foliate attachment disc. It is hollow with three longitudinal canals evident at the point of section (Fig. 19 E) but a single 7 mm diameter canal in the lower stalk. The margin at the junction of inhalant and exhalant surfaces is sharp and lacking obvious large marginal spicules (Fig. 19 F). Spicules are entirely loose in the body, dominated by bundles of long diactins oriented in all directions (Fig. 19 G). In the stalk the main diactins do not occur in bundles but are individually oriented obliquely; they are all fused by spot junctions at contact points and short synapticula between spicules not in direct contact. The second specimen (Fig. 19 B smaller) is a dead, hollow, cylindrical stalk with a foliose basal disc similar to that of the holotype; it is 35.4 cm long and tapers in diameter from 2.8 cm at top to 1.5 cm at its narrowest point. It contains a single axial canal 1.1 cm in diameter at the top. It has been dead for some time and is entirely washed out. Attribution of this specimen to the same taxon as the live spicule-bearing specimen is based upon similarity in size and form of the two stalks, their geographic proximity, 178 km between collection sites, and lack of an alternate appropriate Caulophacus species in the area. Megascleres are hypodermal and hypoatrial pentactins, parenchymal macrohexactins, dermal and atrial pinular hexactins, and parenchymal diactins; all share the same ray end pattern: roughened subterminal area ending in a bare rounded cap (spicule dimensions are given in Table 10). Hypodermal spicules are mainly pentactins (85 %, Fig. 20 A) but some (15 %) have one tangential ray undeveloped and are irregular tetractins. The pentactins have strong, tapering rays, usually without proximal spines but 20 % of tangential rays and 64 % of proximal rays have strong spines adjacent to the spicule center. Ray ends have fine subterminal spined areas but the tips are smooth and rounded. Hypoatrial spicules (Fig. 20 B) are all pentactins similar to those of the dermal side, but slightly smaller and thinner. They more commonly have proximal spines (Fig. 20 B 1) on 64 % of the tangential rays and 80 % of the proximal rays. Parenchymal macrohexactins (Fig. 20 C) are larger than the surface pentactins, but ray form is similar. Proximal spination occurs on at least one ray in 80 % of these but spination on all six rays is uncommon (20 %, Fig. 20 C 1). Parenchymal stauractins occur occasionally. Dermalia (Fig. 20 D), atrialia (Fig. 20 E), and marginalia are similar pinular hexactins with bushy distal rays and vertically spined tangential and basal rays. Great variation of pinular ray form occurs in spicules of both surfaces but the dermal pinular rays are shorter and thicker than those of the atrial side. Pinular spicules are uncommonly pentactine (3 %), and most pinular rays have blunt tips that are overgrown by scales — terminal spines occur in only 25 % of the pinules. Parenchymal diactins (Fig. 20 F) have inflated roughened ends with a small smooth rounded cap. Thinner spicules have four well-developed central knobs but they are insignificant or undetectable in thicker spicules. Microscleres are all variations on a basic form — coarsely-thorned terminal rays ending in hemispheric discs with 3 – 6 large marginal teeth (Fig. 20 G). Discohexatins (Fig. 20 H) are the largest but least common (15 %) of the microscleres. Hemidiscohexasters (Fig. 20 I) with 1 – 3 terminals are the most common (60 %) and intermediate in size. Discohexasters (Fig. 20 J) with 2 – 4 terminals per primary ray are smallest and intermediate in abundance (25 %). The latter two forms have very short terminal rays and some may be considered discasters. Loose spicules in the stalk are hypodermal pentactins and dermal pinules. The hypodermal pentactins are similar to those of the body proper but all lack proximal spines. The pinules consist of approximately equal numbers of hexactine and pentactine forms. A few have very long pinular rays. No microscleres were found in the stalk. Etymology. The species name, adakensis, refers to the location of collection, Adak Canyon. Remarks. The new Aleutian Islands spicule-bearing Caulophacus clearly belongs to subgenus Caulophacus, presently with 18 valid species, by virtue of its possession of only discoid microscleres. Using the simple character of microsclere form, the new specimen is distinguished from 11 species of C. (Caulophacus) by having hemidiscohexasters as its most common microsclere (absent or rare in those 11 species). It is distinguished from 5 additional species by having only spherical discohexasters (stellate or lophoid forms occur in those 5 species). It is most similar to C. discohexaster Tabachnick and Lévi, 2004 but differs in having much larger spherical discohexasters, the mean diameter of the Aleutian Islands specimen (82 – 121 – 165 µm) being outside the entire size range of the New Caledonian form (72 – 108 µm). Comparison of the new form with C. antarctica Schulze and Kirkpatrick, 1910 is not considered possible since very sparse spicules described from the latter (washed-out stalks) are very likely to be extrinsic in origin, or at least not convincingly proper. The Aleutian Islands Caulophacus is thus considered an easily distinguishable new species, designated here as Caulophacus (Caulophacus) adakensis. Review of all video footage collected with the ROV ' Jason II' indicates that this is an uncommon species, occurring singly on bedrock and large boulders at depths between 1326 and 2680 m. The lithodid crab Paralomis verrilli was using the holotype as an elevated perch. Other associated fauna include the demosponge Abestopluma ramosa and the large brittle star Gorgonocephalus eucnemis.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF9236029AD7FD532C88FCEA.taxon	description	Subfamily diagnosis. Saccular Rossellinae with discoctasters. (modified from Tabachnick, 2002: 1448 for the genus Acanthascus). Remarks. Here we formally reject Tabachnick's (2002: 1442) abolition of the subfamily Acanthascinae and propose its reinstatement. We consider the presence of discoctasters as a unique defining feature, at least as important and distinct as the presence of strobiloplumicomes as a defining feature of Lanuginellinae. Schulze's (1893) description of discoctaster structure made it clear that these microscleres have branching of primary rays and fusion of three adjacent components all within the cubic spicule centrum; the bundles of fused primary rays, emanating from the eight apices of the cubic centrum, undergo secondary branching to produce bundles of nearly parallel secondary rays tipped with small discs. We interpret the origin of this special spicule organization as an important innovation that sets the group of descendents apart from other Rossellidae. Tabachnick's (2002: 2992) argument that " discomultiasters " of some caulophacids are superficially similar to discoctasters is considered insignificant to the argument that discoctasters are a unique spicule type. The large externally visible primary rays of those spicules are not formed by regular branching and fusion of internal primary rays to form a basic cubic symmetry and have no relevance to the uniqueness of proper discoctasters. Tabachnick's (2002) primary argument for grouping the three classically recognized genera, Acanthascus, Rhabdocalyptus and Staurocalyptus as subgenera under the single genus Acanthascus rests upon his contention that presence and absence of hypodermal pentactins cannot be considered an important character within Rossellidae. This he supports with the fact that hypodermal pentactins may be absent in some species of Hyalascus and Aulosaccus, and uses that argument to join Aulochone and Crateromorpha within a single genus group, and extends that to join the three Acanthascinae genera within a single genus, Acanthascus. We concur that expression of hypodermal pentactins is variable within the Rossellidae, but we contend that use of selected characters to define subtaxa in different phyletic groups is not inherently defensible. It may be practical to make assumption that a given character, e. g., presence / absence of a spicule type, be used to define genera within a family, but this must be recognized as a subjective presumption that should not be employed carte blanche. On this basis, we do not support grouping the three classical genera within a single genus. However, review of this issue and the group as a whole has led us to conclude that the original diagnoses of the genus-level groups are likely flawed. Their distinction should be first based not upon presence and absence of hypodermal pentactins per se, but upon the presence / absence of a lattice of hypodermal pentactins supporting dermalia, which is absent in Acanthascus and present in Rhabdocalyptus and Staurocalyptus. We reinstate the three genera and provide a new diagnosis for each of them. Genus Acanthascus Schulze Synonymy. Acanthascus Schulze, 1886: 49; part (subgenus Acanthascus) of Tabachnick 2002: 1447. Acanthosaccus Schulze, 1899: 65; Mehl 1992: 92. Part of Bathydorus - B. dawsoni Lambe, 1892: 73.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF9236029AD7FD532C88FCEA.taxon	materials_examined	Type species: Acanthascus cactus Schulze, 1886 Genus diagnosis. Acanthascinae without a continuous hypodermal lattice of large pentactins supporting dermal spicules; occasional individual hypodermal pentactins may occur but they do not form a continuous support for dermalia (new). Remarks. The group, Acanthascus, is restored to genus status as proposed above under Acanthascinae. Original description of the type species, A. cactus, was based upon one specimen obtained by Doederlein in or around Sagami Bay, Japan in the early 1880 s. Specimens from the West Coast of North America with similar spiculation have often been assigned to A. cactus, but, because they lack conspicuous conulation of the body surface, doubt remains that the two populations from coastal NE Pacific and Japan, are genetically linked. A new diagnosis is formed here to accommodate specimens of Acanthascinae that have a few hypodermal pentactins but which do not form a continuous support for dermalia.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF9336069AD7FCEE2A5FFD0B.taxon	description	(Figs. 21 & 22, Table 11) Synonymy. Acanthascus (Acanthascus) profundum ssp. nov. Stone et al., 2011: 26. Material examined. Holotype: USNM # 1196559, ROV ' Jason II' from RV ' Roger Revelle', dive J 2099, 31 July 2004, Adak Canyon, 15.9 km SW of Cape Yakak, Adak Island, Aleutian Islands, Alaska, 51 º 28.091 ' N, 177 º 03.055 ' W, 2105 m, dry & ethanol. Description. The specimen encountered in situ (Fig. 21 A) was a white, thick-walled sac with very large external cones and relatively small circular osculum; before sampling, the specimen measured in situ with lasers was 30 cm tall and 38 cm in widest diameter. The deck photo of the collected upper 2 / 5 ths (Fig. 21 B) shows it was 14.8 cm long by 9.6 cm wide and the large surface cones largely collapsed when removed from water; the basal part was not collected. The very delicate sponge was divided into three parts, one of which was transferred to 95 % ethanol and the other two dried (Fig. 21 C). The wall is up to 2.2 cm thick. Prostalia are entirely lacking. The dermal surface retains indication of the collapsed large cones by small remaining cone tips from which radiate fine surface lines made by tissues associated with trains of hypodermal diactins that crisscross the entire surface. The hypodermal trains support a fine lattice of loose spicules (Fig. 21 D) covering an extensive subdermal space; inhalant canals leaving the subdermal space are 2 – 5 mm in diameter and are conspicuous through the dermal lattice. The atrial surface is extremely irregular, with large deep outpockets mostly 8 – 20 mm diameter extending into the wall; at a finer (mm) scale the surfaces of these outpockets receive small exhalant canals which open directly without a lattice covering (Fig. 21 E). The oscular margin is smooth and rather blunt, without marginalia. The main supporting skeleton is a network of loose interwoven unfused diactins, occurring singly or in bundles, oriented without order. The entire sponge is excessively cavernous and fragile; no spicule fusion is present in the part collected. The fresh specimen is white; when preserved in ethanol or dried it is light brown. Megascleres: (spicule dimensions are given in Table 11). Hypodermalia are diactins; no hypodermal pentactins are present. Dermalia (Fig. 22 A) are mainly pentactins (90 %) with a few hexactins (2 %), irregular tetractins (5 %), stauractins (2 %), triactins (1 %), and diactins (<1 %); rays are finely rough and tips end either bluntly sharp or rounded. Pentactins often have a short stub developed as the sixth ray. Atrialia are regular hexactins (70 %), pentactins (30 %), and a few stauractins with the same ornamentation and ray tips as dermalia (Fig. 22 B). Diactins (Fig. 22 C) are lightly curved, usually without swelling at the axial cross, and smooth except for roughened tips ending as the previous megascleres; they are relatively thin, maximum about 20 µm. Of the two diactine groups examined (Table 11) overlap is great but parenchymal and atrial diactins are generally longer than hypodermal diactins. (dimensions in µm unless otherwise indicated). Microscleres consist of discoctasters, oxyhexactins, and hexasters; discohexasters are absent. Discoctasters (Fig. 22 D) are moderate size with basal half of the primary rays smooth and only the distal half finely rough. Each of the eight primary rays carries 4 – 10 slightly spreading, straight or slightly curved, rough terminal rays ending in marginally serrate discs (Fig. 22 E). The six interradial knobs on the original cube faces are well developed in octasters from both surfaces (Fig. 22 F). Discoctasters from the dermal side are much smaller than those from the atrial plus parenchymal areas (Table 11) and probably represent distinct size classes, but there is considerable overlap and there are no other differences between them (primary to secondary ray lengths are 1.02 for dermal and 0.98 for atrial plus parenchymal). Oxy-tipped microscleres are thin and fragile (Figs. 22 G – I) with short primary rays sometimes subsumed by a swollen centrum, but locations of primary rays always remain clear. They are absent from the dermal surface tissues but abundant in atrial and parenchymal regions. Their forms are mainly hemioxyhexasters (80 %), oxyhexasters (10 %), and oxyhexactins (10 %). Most, but not all, bear reclined spines on their terminal rays that increase in length and density basally; these feather-like basal spines form a conspicuous (in SEM, not LM) dense fringe around bases of terminal rays of hexasters or rays of hexactins (Figs. 22 J, K), while primary rays and exposed centrum surfaces are smooth and without ornaments. In addition, proclined barbs of various lengths occur commonly around the bases of hexaster terminal rays (Fig. 22 J, arrowheads); they are interpreted to be short undeveloped terminal rays. Hexasters bear 1 – 4 terminals per primary ray and, as is common, hexasters are smaller than hexactins. Etymology. The species name is formed in honour of Vladimir Koltun, who produced the basic reference work to North Pacific Hexactinellida, besides his extensive other publications on sponges. Remarks. There are presently only six species / subspecies in Acanthascus sensu stricto. Although the new specimen differs from all known species / subspecies by several characters, it is expedient to list the most obvious. It is excluded from A. cactus Schulze, 1886 and A. pachyderma Okada, 1932 (both with tetractine dermalia) by its possession of mainly pentactine dermalia. The greater length of dermalia tangential ray length in the new form (130 – 178 – 209 µm) excludes it from A. alani alani Ijima, 1898 (125 – 175 µm), A. mitis Koltun, 1967 (110 – 140 µm), A. platei Schulze, 1899 (76 – 132 – 172) and A. sacculus Hernandez, 1932 (105 – 161 µm); the mean of the new form exceeds the greatest range in all four of those noted. Qualitative differences include presence of microdiscohexasters in A. alani alani, A. platei and A. sacculus (absent in the new form) and presence of distinctive hemioxyhexasters with one elongate axis bearing 4 – 5 terminal rays in one plane in A. mitis (no such spicules in the new form). This leaves only A. alani profundum Koltun, 1967 as a potential assignment for it. The Aleutian form, however, differs from A. a. profundum in oxy-microsclere diameter (98 – 199 vs 82 – 148 µm) and absence of the larger discoctaster class (diameter 330 – 425 µm) present in the latter. We conclude from these data that the Aleutian form is a new species, here designated Acanthascus koltuni, n. sp. The new specimen has prompted detailed review of original descriptions of the two subspecies of A. alani. From this process, we propose raising A. alani profundum Koltun to species level, resulting in three closely related North Pacific species of Acanthascus with the following characters (among others). A. alani (subspecies discontinued) occurs shallower than 300 m, has microdiscohexasters, no spurs on oxyhexasters, no oxyhexactine microscleres, and discoctasters of 120 – 220 µm diameter. A. profundum Koltun (n. comb. for A. alani profundum) occurs in deeper water (> 2000 m), has no microdiscohexasters, has spurs on oxyhexasters, has oxyhexactine microscleres, and has two sizes of discohexasters, the larger class 330 – 425 µm in diameter. A. koltuni n. sp., also occurs in deep water (> 2000 m), lacks microdiscohexasters, has spurs on oxyhexasters, has oxyhexactine microscleres, and has two broadly overlapping discoctasters, but the larger is 171 – 286 µm in diameter. All three of these species share conspicuous spines at the base of oxyhexaster terminal rays, most likely derived from their common ancestor. The only collected specimen was attached to a large boulder. Review of all video footage collected with the ROV ' Jason II' indicates that this is a rare species occurring singly on bedrock, mudstone, and large boulders at depths between 1446 and 2245 m.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF9336069AD7FCEE2A5FFD0B.taxon	materials_examined	Type species: Rhabdocalyptus dowlingi Lambe, 1894 Genus diagnosis. Acanthascinae with dermal spicules supported by a continuous hypodermal lattice formed of large pentactins, all of which lack thorns on their tangential rays (modification of Tabachnick 2002: 1451 for subgenus Staurocalyptus). Remarks. The group Staurocalyptus is restored to genus status as proposed above under Acanthascinae. Koltun (1967) designated R. dowlingi Lambe as type species of Staurocalyptus. Tabachnick's (2002) attempt to replace the type species with S. glaber is without merit. His 1999 application to ICZN (case 3104) produced no comment, opinion or declaration and thus his declaration of S. glaber (Tabachnick, 2002) contravened ICZN rules. Lambe's 1894 description was clear and his specimen remains available for inspection at the Canadian Museum of Nature. A new diagnosis is formed here, requiring presence of a supporting lattice of hypodermal pentactins, not simply the presence of a few scattered hypodermal pentactins, for inclusion in Staurocalyptus.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF97361A9AD7FCC12ED3FBF3.taxon	description	(Figs. 23 & 24, Table 12) Synonymy. Acanthascus (Staurocalyptus) sp. nov. 2, Stone et al., 2011: 31. Material examined. Holotype: USNM # 1196560, ROV ' Jason II' from RV ' Roger Revelle', dive J 2104, 05 August 2004, N Amchitka Pass, 50.9 km WSW of Gareloi Island, Aleutian Islands, Alaska, 51 º 39.403 ' N, 179 º 35.041 ' W, 711 m, dry & ethanol. Description. The specimen encountered in situ (Fig. 23 A) was a white, flask-shaped sac with large slightly flaring osculum bordered by a narrow brown fringe, and smooth external surface. Basally it tapered abruptly to a short narrowed stalk ending in a narrow attachment to hard substrate. The collected specimen (Figs. 23 B – C) is 36.5 cm long, 24.5 and 16.3 cm in major and minor diameters (slightly flattened), 3.5 cm thick wall at middle, osculum 15.8 x 8.1 cm in diameters. The general dermal surface, sporting a very few scattered prostal diactins, has evenly distributed 1.9 – 4.0 – 5.9 mm diameter inhalant canals covered by a delicate spicule lattice (Figs. 23 D – F). The atrial surface has a somewhat similar aspect with 2.5 – 4.0 – 7.1 mm diameter exhalant canals but these are covered by a lattice of thick tissue bands (Figs. 23 H, I). Dense prostal diactins, projecting 2.4 – 5.8 – 9.7 mm, and a raised pentactin veil, projecting 0.6 – 1.5 – 2.3 mm, occur only in a narrow band adjacent to the oscular margin and extending only 17 mm below it (Figs. 23 G, J). Sediment trapped in the narrow veil is seen as a brown band in the in-situ image (Fig. 23 A). Special marginalia are not present. In the basal area near the attachment site there occur a few patches of projecting hypodermal pentactins, most with short tangential rays clearly adapted for anchorage rather than supporting dermalia (Fig. 23 K). The entire sponge is fairly firm when fresh and dry; color alive is white, light tan when dried or preserved in ethanol. Megascleres: (spicule dimensions are given in Table 12). Prostal diactins (Fig. 24 A) are slightly curved and taper to rounded finely roughened tips. No middle swelling occurs and an axial cross was not found. Hypodermal pentactins (Fig. 24 B) are abundant in raised position in the submarginal band but not on the lateral body wall. They are moderate in size and mostly paratropal (69 %) but crucial forms are common (27 %). Surfaces are either smooth or shagreened. These spicules are not abundant within the lateral body wall surface, but can be found to occur at ca 3 cm - 2 in digests of large peels. Dermalia (Fig. 24 C) are small, entirely rough pentactins (85 %), with unpaired ray directed inward and small knob in place of sixth ray, hexactins (15 %) and rare stauractins (<1 %); rays are stout and nearly cylindrical and tips are rounded. Atrialia are exclusively regular hexactins (Fig. 24 D) with ornamentation and ray shape like dermalia. Hypodermal diactins (Fig. 24 E left) are slightly curved, with an inflation at the axial cross and rough ends with parabolic tips. Atrial and parenchymal diactins (Fig. 24 E right) are somewhat longer in mean length, but overlap with the hypodermal diactins is extensive. They have similar tips but generally lack the inflation at the axial cross. (dimensions in µm unless otherwise indicated). Microscleres include two sizes of discoctasters, a suite of oxy-tipped hexactins and hexasters, and microdiscohexasters. The discoctasters (Fig. 24 F) have short primary rays and long, straight, rough terminal rays ending in marginally serrate discs. When measured diameters are frequency-plotted (Fig. 24 F inset graph) it is very clear that the two size classes have virtually no overlap, the dermal and parenchymal octasters being only 65 % as large as the atrial octasters. The atrial octasters have proportionately longer terminals. The relatively robust oxytipped microscleres consist of only 10 % oxyhexasters with 2 – 4 terminal rays per primary (Fig. 24 G), 45 % hemioxyhexasters with 1 – 2 terminal rays per primary (Fig. 24 H) and 45 % oxyhexactins (Fig. 24 I). All have rough terminal rays with reclined spines that do not reach the size and density noted above in Acanthascus koltuni. The oxyhexactins are the smallest of these spicules, an unusual condition among Acanthascinae where the oxyhexactins are generally larger than oxyhexasters. The spherical microdiscohexasters (Fig. 24 J) are typical of the subfamily; the very numerous terminal rays end in discs with 4 – 8 marginal teeth. Etymology. The species name, psilosus, is derived from Greek " psilos " meaning smooth, bare, bald, naked, as appropriate to the condition of the extensive outer body surface of the single known specimen. Remarks. The described specimen has discoctasters and large smooth hypodermal pentactins distributed sparsely within the outer lateral body surface and is thus a member of the genus Staurocalyptus. The new specimen can be excluded from the following 7 of the 15 presently accepted species in having mainly pentactin dermalia: S. celebesianus Ijima, 1927, S. glaber Ijima, 1897, S. heteractinus Ijima, 1897, and S. microchetus Ijima, 1898, all have stauractins as the main dermal spicules, while S. hamatus Lendenfeld, 1915, and S. pleorhaphides Ijima, 1897, both have diactins, and S. fuca Tabachnick, 1989 has both diactins and stauractins. By its abundant oxyhexactins, the new specimen can be excluded from S. entacanthus Ijima, 1904 where these are absent or very rare. By its relatively large octasters (162 – 369 µm diam.) the new species is excluded from S. fasciculatus Schulze, 1899 (<100 µm), S. roeperi Schulze, 1886 (120 – 180 µm), S. rugocruciatus Okada, 1932 (<100 µm), S. solidus Schulze, 1899 (134 – 225 µm) and S. tubulosus Ijima, 1904 (130 – 213 µm). Among other qualitative differences, the new form has atrial apertures traversed only by hypoatrial diactine strands while these apertures are either entirely covered by an atrialia lattice in S. fasciculatus or entirely uncovered in S. roeperi, S. tubulosus and S. solidus. The lateral body of the new form lacks a pentactin veil while it is well developed in S. rugocruciatus and S. solidus. This leaves only S. affinis Ijima, 1904 and S. dowlingi Lambe, 1894, both of which are very similar to the new specimen in their known characters. The new species differs from S. affinis in its covered exhalant canals (vs open canals in S. affinis), its lack of hypodermal veil over most of its smooth lateral surface (vs well-developed veil on papillae), its largest hypodermal tangential ray as 3.4 mm x 59 µm (vs 12 mm x 100 µm), its atrial hexactin rays 69 – 132 µm (vs 140 – 240 µm), and its parenchymal diactins to 9.5 mm x 46 µm (vs to 35 mm x 80 – 600 µm). The new species differs from S. dowlingi in its covered exhalant canals (vs open in S. dowlingi), its large atrial canals to 7 mm diameter (vs 0.75 mm), its much smaller prostal diactins to 17 mm (vs to 35 or 60 mm), its hypodermal pentactins being mostly paratropal (vs all crucial), and its larger oxyhexasters 111 – 169 – 212 µm diameter (vs 100 – 159, the largest not reaching the mean of the new specimen). With this suite of differences between the new Aleutian specimen and all present Staurocalytpus species, we conclude that it is a new species, here designated S. psilosus n. sp. The collected specimen was attached to a cobble that was buried in a consolidated mix of cobble and sand. Review of all video footage collected with the ROV ' Jason II' indicates that it is a common species, locally abundant in some areas and occurring singly on bedrock, mudstone, and cobbles at depths between 190 and 1556 m.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF8B361E9AD7FBE02F25FA0D.taxon	description	(Figs. 25 & 26, Table 13) Synonymy. Acanthascus (Staurocalyptus) sp. nov. 1. Stone et al., 2011: 30. Material examined. Holotype: USNM # 1196561, RV ' Velero IV', stn T- 5 E, 6 - m shrimp trawl, 02 July 2004, Adak Canyon, 6.6 km SSE Cape Tusik, Kanaga Island, Aleutian Islands, Alaska, 51 º 37.322 ' N, 177 º 14.350 ' W, 155 m, dry & ethanol; paratype: USNM # 1196562. same trawl / location, dry & ethanol. Description. The holotype is a thick-walled sac (Figs. 25 A, B), fresh on deck measuring 20.7 cm long by 12.8 cm diameter; wall thickness is up to 2.8 cm in the middle. The large terminal osculum has a slight marginal fringe of spicules that do not differ from the sparse lateral prostalia. The outer surface of this trawled specimen is exceptionally ragged with most areas bearing conspicuous bud-like digitate papillae or lobes (Fig. 25 C), which are terminally rounded, each bearing a tuft of prostalia projecting up to 5 mm. Papillae have wide or narrow (stalk-like) attachments to the general body surface; they are 1.3 – 4.0 – 8.6 mm in width (n = 54) and 1.9 – 5.3 – 8.7 mm in height (n = 51). Valleys between the papillae are often deep and extensive, but in areas where papillae are laterally fused to form ridges, the valleys become shorter and, ultimately, in places, rounded holes, 2.9 – 4.2 – 7.0 mm in diameter (n = 14). The paratype (Figs. 25 D, E) is very similar in all characters to the holotype except it is smaller, 8.0 cm long by 6.3 cm diameter, wall thickness to 2.1 cm at middle, has much denser cover of slightly longer prostal diactins (project to 7 mm) and less papillar fusion. Neither specimen has a veil; hypodermal pentactins remain within the outer wall. Exposed surfaces such as tops and sides of papillae, as opposed to the valley floors, are covered by an irregular quadrate lattice of loose spicules with mesh size of 45 – 82 – 113 mm (Figs. 25 F, G); inhalant canals are not visually apparent. The atrial surface is smooth, with visually obvious exhalant canals covered by a coarse irregular spicular lattice formed of hypodermal diactin trains with atrial spicules scattered along those, not forming a rectangular grid; mesh size is 115 – 420 – 883 µm (Figs. 25 H – J). Body texture is soft and pliable; color alive is golden brown, light brown when preserved or dried. Megascleres: (spicule dimensions are given in Table 13). Prostal diactins (Fig. 26 A) are slightly curved and taper to rounded or pointed finely roughened tips. No middle swelling occurs and an axial cross was not found. Hypodermal pentactins are never in a raised position (no veil) and occur in two forms, those with normal proportions (proximal ray length ca 1.5 x tangential ray length) and proximal ray not swollen and those with short tangential rays (proximal ray> 5 x tangential ray length) and proximal ray swollen along upper half (Fig. 26 B). Tangential ray tips are parabolic-rounded and proximal ray tips are pointed; both are rough at ends only. Both are strictly crucial and all tangential rays are smooth, never thorned. Dermalia are relatively small, entirely rough spicules occurring as hexactins (55 %), often with short distal ray, pentactins (36 %) and stauractins (9 %) (Fig. 26 C). Rays are cylindrical and tips are often rounded, but some are parabolic. Atrialia are larger and less rough, occurring as hexactins (94 %) with distal (projecting) ray longer or shorter than tangential rays, pentactins (3 %), and triactins (3 %) (Fig. 26 D). Rays are very slightly tapering and end in sharp tips. Atrial and parenchymal diactins are generally longer and thinner than hypodermal diactins, but they have great overlap. Their measurements are presented separately, but they are morphologically similar (Fig. 26 E), mainly smooth with sharp rough tips, with or without a slight axial swelling. A distinct class of short, stout, rough diactins (not figured) is associated with both subdermal and subatrial areas, but absent from parenchymal tissues. While these are shorter than the normal diactins, they are larger than dermalia and atralia and are not here considered to be part of those assemblages. Microscleres consist of one size of discoctasters, a suite of oxy-tipped forms as mostly oxyhexactins (99 %) and few hemioxyhexasters (1 %), but no fully developed hexasters. All forms are equally abundant in subdermal and subatrial locations. The discoctasters are relatively small, with outcurved floricoidal secondary rays (Fig. 26 F). Primary rays are very short, each supporting 3 – 10 terminal rays ending in symmetric or asymmetrical discs with 10 – 12 marginal teeth. The eight corner projections of the central cube are developed as short digital rays, occasionally bifurcate, instead of the short knobs on most discoctasters. The oxyhexactins (Fig. 26 G) and hemioxyhexasters (Fig. 26 H) are fairly robust and appear smooth in LM, but are found to be sparsely spined in SEM (Fig. 26 I). Hemihexasterous forms have a total of 7 – 10 rays. Small spurs up to 12 µm long occur on about 3 % of oxyhexactins at any point on their rays. Irregular oxy-tipped spicules as pentactins, tetractins, triactins and diactins do occur very rarely. No microdiscohexasters or their parts were found in extensive searches. Etymology. The species name, tylotus, is derived from Greek " tylotos " meaning knobby, appropriate to the condition of the outer papillate surface. Remarks. Only 2 of the presently recognized 15 Staurocalyptus species have discoctasters less than 100 µm in diameter, S. fasciculatus Schulze, 1899 and S. rugocruciatus Okada, 1932. Review of type specimens and original descriptions of both show neither of these species is suitable for assignment of the new Aleutian specimens. The discoctasters of both species have short, straight, tightly bundled terminal rays in contrast to the out-curved, long terminal rays in the floricoidal forms of the Aleutian specimens. Other differences are that both species are thinwalled, 3 mm and 8 mm respectively, in contrast to the 28.0 mm and 20.8 mm of the new specimens. Staurocalyptus fasciculatus has no projecting prostalia and S. rugocruciatus has a veil of projecting hypodermal pentactins, both features differing from those of the new specimens. These differences indicate that the Aleutian specimens represent a new species, here designated S. tylotus. Floricoidal discoctasters also occur in Rhabdocalyptus unguiculatus Ijima, 1904, and R. bidentatus Okada, 1932. If this similarity is seriously considered or proven to be phylogenetically shared, it could serve as an argument for discounting the importance of hypodermalia thorns and lead to a reorganization of the present grouping of acanthascid species. The new specimens were collected on relatively flat seafloor composed of sand, pebbles, and cobbles. They were attached to small cobbles and pebbles imbedded in the sediment. Review of all video footage collected with the ROV ' Jason II' indicate that it is a common species, locally abundant in some areas and occurring at depths between 139 and 183 m. No in situ images are available for this species. Genus Rhabdocalyptus Schulze Synonymy. Rhabdocalyptus Schulze, 1886: 51. Part of Acanthascus - Tabachnick 2002: 1447. Part of Acanthosaccus - A. tenuis Schulze, 1899: 65. Subgenus Rhabdocalyptus Tabachnick 2002: 1449. Type species: Rhabdocalyptus mollis Schulze, 1886 Genus diagnosis. Acanthascinae with large pentactins that form a continuous hypodermal lattice supporting smaller dermal spicules; some hypodermal pentactins bear large thorns on their tangential rays (modified from of Tabachnick 2002: 1450 for subgenus Rhabdocalyptus). Remarks. The taxon Rhabdocalyptus is reinstated as a genus-level group as proposed above under Acanthascinae.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
03D287B2FF8F36159AD7F9C12CD2FC17.taxon	description	(Figs. 27 & 28, Table 14) Synonymy. Rhabdocalyptus mirabilis Schulze, 1899: 61. Acanthascus (Rhabdocalyptus) mirabilis Stone et al., 2011: 28. Material examined. USNM # 1196563, ROV ' Jason II' from RV ' Roger Revelle', dive J 2105, 06 August 2004, Amchitka Pass, 11.4 km WNW of Cape Sajaka, Tanaga Island, Aleutian Islands, Alaska, 51 º 54.253 ' N, 178 º 23.235 ' W, 2311 m, dry & ethanol, base not collected. Comparative material. Rhabdocalyptus mirabilis, holotype, USNM 07574, USFS ' Albatross', stn 3338, 28 Aug. 1890, S of Shumagen Bank, Alaska, 54 º 19 ' N, 159 º 40 ' W, 1143 m, ethanol; Rhabdocalyptus sp., USNM 07573, USFS ' Albatross', stn 3008, 18 Mar. 1891, Gulf of California, 26 º 00 ' N, 111 º 06 ' W, 560 m, ethanol & dry. Description. The specimen in situ (Fig. 27 A) was a curved, white, tubular sponge, 15.5 cm long by 10.1 cm diameter, with well-developed spicule veil and large terminal osculum. The major part of the specimen, but not the basal attachment, was collected, and after drying (Fig. 27 B) is 14.0 cm long by 6.8 cm in flattened width and wall thickness to 6.0 mm. Prostal diactins project 10 – 15 mm only from the oscular margin (Fig. 27 C) and a narrow 12 mm wide band of lateral surface below it; they are not found on most of the lateral surface. Raised hypodermal pentactins forming the veil, all paratropal and thorned, project nearly continuously to 3.4 mm in the diactin zone around the oscular margin and as small groups of 3 – 8 pentactins to 7.3 mm from the tips of low conules over most of the lateral body surface (Fig. 27 D). Conules are 4.2 – 6.5 – 9.2 (n = 36) mm apart and 0.8 – 1.2 – 1.5 (n = 16) mm high. Short extremely paratropal pentactins with all four tangential rays emanating as a tight bundle within 15 ° (Fig. 27 E) occur in the dense veil near the oscular margin but not over the general lateral body veil. The dermal surface is turned in ca 2 mm at the osculum margin forming a narrow diaphragm. The lateral dermal surface (Fig. 27 F) is covered by conspicuous inhalant canals, 1.1 – 2.1 – 3.0 (n = 41) mm in diameter, and, although these apertures are covered by a dermal lattice (Fig. 27 G), it is irregular and so delicate and thin that it reflects very little incident light. The atrial surface bears apertures of larger exhalant canals, 1.6 – 2.9 – 5.9 (n = 62) mm in diameter, but they are covered by a firm, rather opaque lattice supported by hexactins with longest ray protruding into the atrium (Figs. 27 H, I). Hypoatrial diactin strands do not support the atrial lattice over the exhalant apertures but are found below the lattice in the wall between the canal apertures. The sponge is very soft and delicate when fresh; color alive is white but when preserved or dried it is light tan. Megascleres: (spicule dimensions are given in Table 14). Hypodermal pentactins (Figs. 28 A – C) have considerable variation; all of those raised above the lateral surface are large, paratropal and thorned (Fig. 28 A). Those within the general lateral surface include both large and small, tangential rays either thorned, smooth or shagreened, and paratropal or crucial in shape. Thorns, up to 94 µm long, are always nearly perpendicular proximally and gradually more inclined distally. Restricted to the dense suboscular veil are small hyper-paratropal (Fig. 28 B) and very small crucial (Fig. 28 C) forms, both with shagreened tangential rays. Dermalia (Fig. 28 D) are mainly diactins (97 %), with all other varieties, monactins, irregular diactins, triactins, tetractins, less than 1 % each. These have slightly tapered rays ending in abruptly sharp or parabolic tips; they are entirely finely spined and vary in degree of formation of the knobs at the axial cross — typically the diactins have two, sometimes one reduced ray knob, but never indication of four reduced rays. Atrialia (Fig. 28 E) are subpinular hexactins (99 + %) and a very few pentactins (<0.1 %); the projecting distal ray is longer and has larger spines than the other rays. Rays are tapered, entirely smooth only in the proximal third, and end in pointed tips. Parenchymal diactins (Fig. 28 F) are here arbitrarily divided into thicker (> 35 mm thick, as principalia) and thinner (<35 µm thick) subgroups, but diactin length and width are probably continuously variable from prostal diactins to the smallest comitalia. Parenchymal diactins are mainly sinuously curved spicules, cylindrical and smooth, with rough ends terminating in rounded or very bluntly sharp tips. Prostal diactins (Fig. 28 G), easily identified by their projection from the upper dermal surface, are mostly smooth, occasionally shagreened in patches, and have rough rounded tips; their axial cross could not be found. Microscleres include one class of discoctasters, a suite of oxy-tipped forms consisting of oxyhexactins (80 %), hemioxyhexasters (15 %) and oxyhexasters (5 %), and microdiscohexasters. The discoctasters (Fig. 28 H) have short primary rays, each bearing 5 – 9 – 12 long, rough terminal rays that splay strongly outward in floricoidal pattern and end in marginally serrate discs with 4 – 7 marginal teeth that project proximally. Interradial knobs are short and hemispheric. Discoctasters occur primarily in atrial and subatrial tissues and are entirely absent in dermal or subdermal tissues. Oxyhexactins (Fig. 28 I) have straight, tapering, finely rough rays that lack a basal inflation. The reclined spines are more dense basally, but they do not form a striking skirt at the centrum. Hemioxyhexasters (Fig. 28 J) have extremely short primary rays, each supporting 1 – 3 terminal rays with same form and orientation as those of oxyhexactins. Oxyhexasters (Fig. 28 K) are similar, with each primary ray supporting 2 – 4 terminal rays. Very few smaller oxyhexasters with hooked ray ends occur in spicule preparations, but it remains uncertain if these are proper or contaminants. The size gradation of smaller hexasters, larger hemihexasters, and largest hexactins seen in most lyssacinosids is exhibited here. Microdiscohexasters (Fig. 28 L) have short, very thick primary rays, each supporting numerous (6 – 12) straight, curved or sinuous terminal rays ending in minute discs. They occur only in dermal tissues. Remarks. The new described specimen has large thorned hypodermal pentactins distributed sparsely within the outer lateral body surface and discoctasters and is thus a member of the genus Rhabdocalyptus. The new specimen can be excluded from four of the five known species of the genus that have diactins as their principal dermal spicules. Rhabdocalyptus australis Topsent, 1901, from Antarctica, has atrial spicules with equal ray lengths, has octasters with cylindrical terminal ray tufts, and has no discohexasters. Rhabdocalyptus capillatus Ijima, 1897, from Japan, has smaller atrial spicules (tangential ray length 126 – 220 µm vs 191 – 316 µm here) and much smaller discoctasters (diameter 76 – 94 – 110 µm vs 144 – 163 – 180 µm here). Rhabdocalyptus mollis Schulze, 1886, from Japan, has atrialia with equal length rays, discoctasters that are mainly subdermal, and smaller discohexasters (diameter 22 – 27 µm vs 21 – 40 µm here). Rhabdocalyptus unguiculatus Ijima, 1904, from Japan, shares the floricoidal form of discoctasters with the new form but has much thicker principal diactins (to 175 µm vs 113 µm here), much larger discohexasters (diameter 175 – 190 vs 145 – 163 – 180 µm here), and smaller microdiscohexasters (22 – 30 µm vs 21 – 40 µm here). The new specimen agrees completely with the original description of R. mirabilis Schulze, 1899, from south of the Alaska Peninsula, and is confidently assigned to that species. The specimen, USMN 07573, from the Gulf of California is listed as R. mirabilis on label and catalogue, but although it was compared to R. mirabilis by Schulze (1899), he concluded that it must remain R. sp.; he did not provide reasons for that conclusion. In review of the extremely damaged specimen, we find it has discoctasters (diameter 127 – 167 – 205 µm, n = 64) very similar in size and shape to those of R. mirabilis, but it does not have diactin dermalia nor does it have oxyhexactins as the major microsclere; it has pentactins and oxyhexasters respectively. The Gulf of California specimen is clearly not R. mirabilis and must remain as R. sp. until that local fauna is better known. Justification for description of the new Aleutian specimen is the fact that this is only the second reported specimen of R. mirabilis, and the first known since Schulze's original 1899 description of a partial top end of the original specimen. We also provide the first SEM figures and complete spicule data set for this species. Review of all video footage collected with the ROV ' Jason II' indicate that it is a rare species occurring singly on bedrock at depths between 1984 and 2790 m.	en	Reiswig, Henry M., Stone, Robert P. (2013): <strong> New glass sponges (Porifera: Hexactinellida) from deep waters of the central Aleutian Islands, Alaska </ strong>. Zootaxa 3628 (1): 1-64, DOI: 10.11646/zootaxa.3628.1.1, URL: http://dx.doi.org/10.11646/zootaxa.3628.1.1
