taxonID	type	description	language	source
F24C880C1F459D2E6093A43EFD07FE27.taxon	materials_examined	Material. Four individuals studied alive, five sagittally-sectioned specimens (ZMUG 23317 - 23321).	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F459D2E6093A43EFD07FE27.taxon	discussion	Remarks. The Galapagos specimens can easily be identified as P. e u r y t u b a, based on the overall organisation of the body, the morphology of the proboscis hooks and that of the stylet. As the original description by Ax and Armonies (1987) and a later account by Ax (1997) were based only on observations on live animals, very little is known of the detailed morphology, and a reconstruction of the genital system is lacking. The new material from the Galapagos allows a detailed and more complete description, although certain features are still hard to discern, especially concerning details of the female system, which appears to be difficult to study in members of the taxon Prognathorhynchus Meixner, 1929 (see Karling 1947; Brunet 1973; Ax & Armonies 1987). Live animals about 0.7 − 0.8 mm long. The cellular epidermis (± 5 µm thick) is ciliated over the entire body (cilia ± 5 µm long). A few sensory bristles (± 20 µm long) are present around the proboscis opening. The proboscis hooks (Fig. 1 C) are as described by Ax and Armonies (1987), only slightly larger. The diameter of the basal plate is ± 25 µm (Ax & Armonies 1987: 17 µm). The stylet’s (Fig. 1 B) shape is as illustrated by Ax and Armonies (1987). The stylet length in the Galapagos specimens varies from 42 − 48 µm (x = 45 µm; n = 3), which is longer than in the Canadian (Ax & Armonies 1987: 32 µm) and the specimens from South Carolina (Ax 1997: 35 µm). The common genital pore (Fig. 1 A, D: gp) is situated ventrally, very close to the caudal end and opens into a tubiform common genital atrium, which is lined with a low, anucleated epithelium and is surrounded by a longitudinal muscle layer. Basophilic caudal glands are situated on both sides of the genital atrium. The genital atrium receives the male system from the dorsal side, and both the female system and the uterus from the rostral side. The elongated seminal vesicle is surrounded by strong longitudinal muscles with an oblique orientation in the proximal part. Sperm is discharged through the funnel-shaped opening of the stylet (see also Ax & Armonies 1987 and Ax 1997), whereas the globular prostate vesicle, which contains a coarse-grained basophilic secretion and which is surrounded by circular muscles, discharges through the second, smaller opening of the stylet. The stylet lies in the oviform male atrium, which is surrounded by longitudinal muscles and lined with a very low, anucleated epithelium. From the single ovary, the female duct, which is lined with a very low, anucleated epithelium and only distally surrounded by longitudinal muscles, runs ventro-caudally towards the common genital atrium. A very large and vaguely defined bursa contains numerous large nuclei and sperm in different stages of degeneration as well as live sperm, organized in separate compartments. From one of these compartments a curved spermatic duct (Fig. 1 D: ds), surrounded by longitudinal muscles, runs towards the ovary, although the connection proper is hard to discern. A vaginal pore (Fig. 1 A, D: vp), situated rostrally from the common genital pore, is clearly visible on all sectioned animals, but could only be observed in one out of four live specimens. It is surrounded by a strong sphincter and continues into a vaginal duct, which is surrounded by circular muscles and which leads to the bursa. In the diagnosis for the taxon Gnathorhynchidae by Karling (1947), the presence of only a single genital pore is mentioned. Also Ax and Armonies (1987) and Ax (1997) do not mention a vaginal pore for P. eurytuba. However, a second opening of the genital system (i. e. a vaginal pore as in P. e u r y t u b a) is also observed by Hochberg (2004) in P. busheki Ax, 1997, using confocal laser scanning microscopy. Apart from P. busheki and P. e u r y t u b a at least two other species of Prognathorhynchus have a female bursa functioning as a seminal receptacle: P. parvulus Brunet, 1973 and P. dividibulbosus Ax & Armonies, 1990. As the vaginal pore is often very difficult to see in live specimens, and many of the species of Prognathorhynchus were described without sectioned material, it is possible that a vaginal pore is present in more (even all?) species of this taxon, especially in those in which the presence of a female bursa has been recorded. It is, therefore, apparent that the taxa Prognathorhynchus and Gnathorhynchidae are highly in need of taxonomic revision. It should be checked on animals from the Atlantic populations of P. e u r y t u b a whether they indeed are identical in all details to the population from Galapagos, and hence indeed belong to the same species. The disparate distribution, indeed, could indicate a geographical isolation of both populations. At the moment, however, we cannot but consider the Galapagos population as belonging to the same species, as at this moment no fixed morphological differences between the two populations can be found.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F479D296093A3A1FE5EFD3C.taxon	materials_examined	Material. Several specimens studied alive. A total of 42 serially-sectioned animals, one of which is designated holotype (ZMUG 23231), 13 others designated paratypes (ZMUG 23232 - 23244). Voucher specimens deposited as ZMUG 23252 - 23279.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F479D296093A3A1FE5EFD3C.taxon	etymology	Etymology. Species name refers to the presence of two symmetrical atrial glands. Glandula (Lat.): gland.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F479D296093A3A1FE5EFD3C.taxon	diagnosis	Diagnosis. Species of Itaipusa Marcus, 1949, with two atrial glands symmetrically located beside the female duct; male system with a short, unarmed penis papilla; large bursa with resorptive part and muscular bursal stalk opening into female duct.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F479D296093A3A1FE5EFD3C.taxon	description	Description. Live animals ± 1.3 mm long, caudally rounded, with two eyes. The syncytial epidermis is ± 6 µm thick and shows a prominent basement membrane. It contains numerous apically-elongated, oviform, 2 − 4 µm long rhabdites, which are absent in the head region, from the anterior tip to half the proboscis length. The animal is ciliated over the entire body (cilia ± 6 µm long) with sensory bristles (± 25 µm long) surrounding the proboscis opening. The proboscis measures almost 1 / 5 of the body length and shows the characteristic features of a typical koinocystidid proboscis (see Brunet 1972; Karling 1980). It has a very strong Itaipusa - type proboscis juncture sphincter (see Karling 1980: p. 260). The pharynx is situated at about 40 %, and does not show any peculiarities in comparison with other species of Itaipusa or Koinocystididae in general (see Meixner (1925) and Karling (1954, 1980) for a detailed account). The oesophageal glands, clearly visible in sectioned material, are not distinguishable on live animals. A pharynx mouth sphincter could not be observed on sectioned specimens. Male and female gonads are paired. The oval testes lie dorso-laterally, caudally from the pharynx, extending to the distal part of the ovaries, which are situated at ± 75 %. The vitellaria extend from the mouth to the ovaries, the anterior part being situated dorso-laterally, whereas the posterior part lies more central and ventrally to the testes. The common genital pore, situated at ± 90 %, opens into the common genital atrium, which is lined with a high, nucleated epithelium and is surrounded by longitudinal muscles. Anteriorly it receives the uterus, and the male duct more dorsally. The female system opens into the genital atrium from the dorso-caudal side. The elongated, paired seminal vesicles are lined with a low, nucleated epithelium and surrounded by longitudinal muscles. Both vesicles fuse just before entering the prostate vesicle, forming the ejaculatory duct. This duct runs centrally through the prostate vesicle and is surrounded by eight to ten filiform prostate gland necks, called prostate ducts by Karling (1980). The prostate glands proper are very large, surrounding the seminal vesicles and containing one type of basophilic, coarse-grained secretion. The almost globular prostate vesicle bulges into the male genital atrium in a short, muscular penis papilla. The exact course of the ejaculatory duct could not be revealed, except for its distal part that opens into the penis papilla. This part of the ejaculatory duct is surrounded by circular muscles. The male atrium is lined with a low, anucleated epithelium and does not seem to be surrounded by a muscle layer. The ovoid ovaries have short oviducts, which join to form the female duct and are lined with a low, anucleated epithelium. On this bifurcation, a short vitelloduct enters the female duct. This female duct is lined with a low, nucleated epithelium and surrounded by weak, circular muscle fibres, forming a strong sphincter distally. Although no sperm could be observed in this duct, it probably acts as a seminal receptacle, indicated by the fact that it is swollen in all specimens. Instead of opening into the common genital atrium, it is connected to a very muscular bursal stalk, which enters the atrium dorso-caudally, together with two symmetrically-placed, glandular complexes with fine-grained eosinophilic secretion (Fig. 2 B: gl). Over its whole length this stalk is surrounded by circular muscles, which are extremely thick proximally, close to the bursal organ proper, forming two very large sphincters. The bursa acts as a sperm-resorbing organ (resorptive vesicle of Karling 1980). The bursa has a nucleated epithelium, which merges with the sperm-resorbing mass more proximally. The uterus is lined with a high, nucleated epithelium and surrounded by spirally-running muscle fibres. It opens into the common genital atrium close to the genital pore and is provided with two types of glands. The first type contains a fine-grained eosinophilic secretion and is situated near the proximal end, although the exact location of the opening into the uterus is unclear. More distally a coarse-grained basophilic gland type is present. These glands open into the uterus lumen half way along the organ.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F479D296093A3A1FE5EFD3C.taxon	discussion	Discussion. See the general discussion on Itaipusa following the remarks on I. variodentata (Karling et al., 1972) Karling, 1978.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F409D286093A664FEE5FBDC.taxon	materials_examined	Material. Galapagos: two individuals studied alive, nine serially-sectioned ones (ZMUG 23280 - 23288). Curaçao: several individuals studied alive, five whole mounts, two serially-sectioned specimens (HU IV. 4.11 - IV. 4.17).	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F409D286093A664FEE5FBDC.taxon	discussion	Remarks. The general organisation of our specimens corresponds well with the observations by Marcus (1949), including the fact that the epidermis is syncytial. As mentioned earlier by Karling (1980) the exact course of the female duct is hard to discern. In both live and sectioned animals, the numerous small hooks on the sclerotized folds of the cirrus are longer than the 2 µm mentioned by Marcus (1949). The pictures (see Fig. 3 B for one of them) of the two specimens from Galapagos show hooks with a length of ± 4 µm on all sclerotized folds. This is also the case in the specimens from Curaçao, with exception of one specimen that shows a few areas of the sclerotized folds with smaller hooks (1 − 2 µm). On the syntype, Karling (1980) observed some areas with rather large hooks (4 − 7 µm). This observation indicates that, possibly depending on the area of cirrus, the hooks may vary in length between 1 and 7 µm. In the Galapagos specimens studied alive, the course-grained basophilic prostate ducts have a more saccular appearance. In the sectioned material of both the Galapagos and Curaçao, the exact form of the ducts is not well visible, except in two specimens from Galapagos where these ducts are filiform, at least in the distal part of the prostate vesicle. Pictures of the Galapagos specimens reveal large (secretion?) granules scattered around the distal part of the ejaculatory duct, which could not be found again in the sectioned material. Nevertheless, in all sectioned specimens some ill-defined, fine-grained, eosinophilic secretion could be observed near to the distal part of the prostate ducts.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F4C9D256093A1BBFD16FD7F.taxon	materials_examined	Material. Four specimens studied alive, 28 specimens serially-sectioned (ZMUG 23289 - 23316).	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F4C9D256093A1BBFD16FD7F.taxon	discussion	Remarks. The complex structure and orientation of the organs in the specimens studied alive are in accordance with the observations of Karling et al. (1972) on specimens from Hawaii. On sections it is clear that the epidermis is cellular, showing distinctly-delimited epidermal cells as was mentioned in the original description (Karling et al. 1972). The Galapagos specimens (3 mm long) are, however, clearly larger than those from Hawaii (Karling et al. 1972: 2 mm). The two hooks of the copulatory organ clearly differ in size in comparison with those from Hawaii. The smaller hook measures 52 − 108 µm (x = 86 µm; n = 4), whereas the larger one measures 75 − 140 µm (x = 102 µm; n = 4). This is significantly larger than what was observed by Karling et al. (1972): 30 µm for the small hook and 37 µm for the large hook. However, since no other differences could be observed and since molecular data are lacking in order to back up a splitting of the species, we deliberately choose not to describe the population from the Galapagos as a separate species for the time being.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F4D9D216093A548FE59FE54.taxon	materials_examined	Material. One specimen studied alive and one serially-sectioned specimen designated holotype (ZMUG 23251).	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F4D9D216093A548FE59FE54.taxon	etymology	Etymology. The genus name is a contraction of “ Galapagos ”, and “ Getula ”, a resembling taxon. Species name dedicated to Annika Willems, daughter of the second author. Diagnoses. Galapagetula n. gen. Koinocystididae with proboscis of the typical koinocystidid construction without proboscis juncture sphincter; pharynx without a mouth sphincter; testes at mid-body; copulatory organ pearshaped, distally cylindrical with a long, folded cirrus, armed with small spines; female duct proximally widened, functioning as seminal receptacle, distally highly muscular with strong sphincter; muscular bursa and resorptive bursa opening separately into the female duct. Type species (by original monotypy): Galapagetula annikae n. sp., provisionally with the same diagnosis as the genus.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F4D9D216093A548FE59FE54.taxon	description	Description. Live specimen grey, spindle shaped, with two eyes. It is ± 1.2 mm long. The syncytial epidermis (± 10 µm thick) has a prominent basement membrane and contains numerous oviform rhabdites (2 − 4 µm long). They are absent from the anterior tip to half way along the proboscis. The animal is ciliated over its entire body surface (cilia ± 6 µm long), with some sensory bristles around the proboscis opening. The proboscis is about 1 / 5 of the body length. It has the characteristic traits of a koinocystidid proboscis (see Brunet 1972; Karling 1980). As far as could be derived from the sections, a proboscis juncture sphincter is absent. The pharynx is situated at 35 % and shows no distinct pharynx mouth sphincter. Unfortunately, the material does not allow a detailed reconstruction of the pharynx and the proboscis. Observations indicate that the pharynx contains a fine-grained eosinophilic and coarse-grained basophilic secretion. The lumen is lined with a membranous epithelium. Male and female gonads are paired and situated in the posterior half of the body. The oval testes lie dorso-laterally, at the beginning of the second half of the body. The spindle-shaped ovaries are situated at ± 75 %. The short vitellaria lie ventro-laterally and extend from the level of the testes to the ovaries. The common genital pore is situated at ± 85 % and opens into the globular common genital atrium, which is lined with a nucleated epithelium and surrounded by an outer longitudinal and a less prominent, inner circular muscle layer. It receives the uterus and the male and female genital system at three different “ levels ” (see schematic overview in Fig. 5 B). The elongated uterus enters the common genital atrium rostro-ventrally, with the male copulatory organ situated just dorsally to the uterus and also opening into the atrium from the rostral side (Fig. 5 A: Level I; Fig. 5 C). The female system enters the atrium from the dorsal side (Fig. 5 A: Level II; Fig. 5 D). The most distal part of the female duct, which is highly muscular, receives two different bursal organs Fig. 5 A: Level III; Fig. 5 E). The male genital system consists of an oval to pear-shaped copulatory organ with an armed cirrus. The seminal vesicles are almost globular and lined with a low, nucleated epithelium and surrounded by a spirally – running, almost circular muscle layer. Distally from the seminal vesicles, the vasa deferentia fuse just before entering the prostate vesicle, forming an ejaculatory duct that contains sperm in its proximal part. This duct runs centrally through the prostate vesicle and is surrounded by several prostate ducts with coarse-grained basophilic secretion. The cell bodies of the prostate glands are visible beside the seminal vesicles and the prostate vesicle (Fig. 5 C: pg). The exact course of the prostate ducts is difficult to discern, but there are indications that they enter the prostate vesicle a little distally from the ejaculatory duct. The muscle layer surrounding the seminal vesicles continues around the prostate vesicle. In contrast to observations on the live animal, the trajectory of the individual prostate ducts and the ejaculatory duct are not clearly visible on the sectioned material. However, they most probably enter the proximal part of the cirrus, which is situated in the most distal half of the male copulatory organ. The cirrus is lined with a thick basement membrane, which forms numerous minute, scale-like hooks (0.1 µm or less). The cirrus proper is surrounded by an inner layer of circular muscles and an outer layer of longitudinal muscles. It is folded, making its course very hard to reveal. At its distal end it forms a penis papilla-like structure, which protrudes into the male duct. The elongated, almost spindle-shaped ovaries are connected to the female duct by short oviducts, which are surrounded by longitudinal muscles and are provided with a weak distal sphincter (Fig. 5 D: sph 1). An epithelium could not be observed. Both vitelloducts fuse into a very short single duct, which is provided with a strong sphincter, just before entering the female duct in between the two oviducts (see Fig. 5 D: sph 2). The most proximal part of the female duct is surrounded by circular muscles. As for the oviducts, an epithelium cannot be seen. The female duct is clearly widened and contains many vitellocytes and some sperm close to the oviducts, functioning as a seminal receptacle. More distally it narrows and can be closed by a very strong sphincter (see Fig. 5 D: sph 3). From this point the female duct is lined with pseudocuticle (dense and thickened basement membrane not covered by epithelium) and surrounded by a very thick circular muscle layer, before entering the muscular bursal stalk. The bursal system consists of a muscular bursal stalk, which proximally ends in a large bursa (Fig. 5 A, B, E: bu 1). The bursa is lined with a nucleated epithelium and filled with a mass of different density, wherein several nodular structures and clusters of sperm can be recognised. The bursal stalk also forms a very muscular diverticulum which contains some sperm and is lined with a thick irregularly-folded pseudocuticle: the accessory bursa (Fig. 5 A, B, E: bu 2). It is surrounded by strong circular muscles that stain rather weakly compared to those of the female duct. The uterus is lined with a nucleated epithelium and surrounded by spirally-running muscle fibres, distally continuing as longitudinal muscles. At the distal end a second outer circular muscle layer is present around the stalk. Two types of uterus glands are present: fine-grained eosinophilic ones proximally and coarse-grained basophilic ones distally.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F4D9D216093A548FE59FE54.taxon	discussion	Discussion. The new species shows all features mentioned in the diagnosis of the taxon Koinocystididae, given by Karling (1980). However, the specific combination of features shown by this species is unique, and does not allow its placement in any existing genus. The only other taxa without a proboscis juncture sphincter within Koinocystididae are Axiutelga Karling, 1980, Getula Karling, 1980, Itaipusina Karling, 1980, Leguta Karling, 1980, Parautelga Karling, 1964, Pontaralia Mack-Fira, 1968, Rhinolasius Marcus, 1951 and Utelga. G. annikae clearly differs from all these taxa, and the other koinocystidids, in the presence of the accessory bursa. In a number of species (e. g. Itaipusa ruffinjonesi) the bursal stalk is enlarged towards the entrance of the seminal receptacle, an enlargement called “ receptacle bursa ” by Karling (1980). The position of the accessory bursa in G. annikae is, however, clearly different from that of the “ receptacle bursa ” described by Karling (1980). The fact that the epidermis is syncytial is not uncommon within the Koinocystididae. For a discussion on this topic, see the discussion on Itaipusa. A cirrus provided with uniform, small spines is also rather exceptional within Koinocystididae. Either the cirrus is unarmed, or the spines are not uniform, or additional large hooks are present. Basically, only in Axiutelga does the cirrus show uniform, albeit much larger spines than in G. annikae (7 − 10 µm and 0.1 µm respectively). The unique construction of the female system combined with a uniformly-spined cirrus warrants the erection of a new genus for G. annikae.	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F489D216093A0F0FC4CFC71.taxon	materials_examined	Material. One individual studied alive, one sagittally-sectioned specimen (ZMUG 23322).	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
F24C880C1F489D216093A0F0FC4CFC71.taxon	discussion	Remarks. The internal structure is in accordance with the observations and remarks by Karling (1954, 1980). The epidermis is clearly cellular, as was mentioned by Karling (1954). One of the hooks associated with the copulatory organ is 40 µm long, slightly larger than the other two (35 µm). These two smaller hooks also differ slightly in shape from the third, larger hook. Their basal plate is smaller and the gutter-shape of the spine-like part is less prominent. Although the measurements are slightly larger, they correspond well with earlier data (e. g. Karling 1954: 22.5 − 28 µm; Karling 1980: 22 − 35 µm; Willems et al. 2007: 10 − 23 µm). Difficulties with interpretation of shape and size of the hooks are mentioned by Willems et al. (2007).	en	Reygel, Patrick C., Willems, Wim R., Artois, Tom J. (2011): Koinocystididae and Gnathorhynchidae (Platyhelminthes: Rhabdocoela: Kalyptorhynchia) from the Galapagos, with the description of three new species. Zootaxa 3096: 27-40, DOI: 10.5281/zenodo.200746
