Boltenia australiensis, Carter, 1885

Gunther, Albert C. L. G., Dallas, William S., Carruthers, William & Francis, William, 1885, The Annals and Magazine of Natural History, Including Zoology, Botany, and Geology, Reptiles and Batrachians from Brazil, LONGMANS, GREEN, AND CO.; SIMPKIN, MARSHALL, AND CO.; KENT AND CO.,; WHITT AKER AND CO.: BAILLIERE, PARIS: MACLACHLAN AND STEWART, EDINBURGH: HODGES, FOSTER, AND CO., DUBLIN: AND ASHER, BERLIN: TAYLOR AND FRANCIS, pp. 1-96 : 197

Boltenia australiensis (provisional).

There are three or more specimens of this Boltenia in the collection, together with a sessile Ascidian of the common stalkless form, all covered with a layer of this Halisarca , about l-24th in. in thickness; but there is only one Boltenia in which the stem is perfect, and here it is 17 in. long with a diameter of 7-2libs in. where it joins the head, and one of l-4th in. below, where it ends in a root-like ex ­ pansion; while the head, which is nodosely tubercular all over except towards the lower part, is 3 in. high by 2 x I in. in its greatest dimensions; and yet the whole, from top to bottom, is covered by a layer of the Halisarca . Both the head and stem are composed of firm whitish cartilage, and the nodosely tuberculated surface of the former covered by the llalisarca tends greatly to obscure the position of the openings of the Ascidian. Internally the head is smooth, corresponding with the form of the Ascidian which it contains, so all the rest must be viewed as the test, connected only with the Ascidian itself by vascular extension from the latter, which here most strikingly manifests its presence by two large vessels (? artery and vein) which, side by side, longitudinally and centrally extend throughout the stem. But the most remarkable part of the stem is that, being almost entirely composed of the white or colourless cartilage, it has imbedded in its structure a thin cylindrical layer of reticulated, anastomosing, keratose, solid, laminated, amber-coloured fibre, so similar to that of a keratose sponge, that, if the two were placed together, it would be almost impossible to distinguish between them. This is situated just inside the circumference of the stem in the midst of the white cartilage, where, by its amber-yellow colour, it contrasts strongly with the latter. It extends from one end to the other of the stem, to which it appears to be confined, disappearing equally towards the head and in the branches of the root-like expansion. Nowhere does the presence of the Halisarca . appear to influence the form of the test, which is as smooth over the nodosely tuberculated head as it is over the even surface of the cylindrical stem. How far the Ascidian itself may be identified with Prof. Herdman ’s Boltenia pachyderniatina (‘ Challenger ’ Reports, pt. xvii. p. 89) I am not prepared to say; but as I find specimens of both in Mr. Wilson ’s collection, 1 can with confidence state that there is considerable difference between the forms of the tests and the composition of their stems gene ­ rally. That which corresponds to the description of Boltenia pachydermatina is not covered with Halisarca , while the smooth, wrinkled, and horn-like corrugated stem presents no keratose fibre, but is charged with little calcareous spicules extending inwards for about 1-lSOth in.; inside which the cartilage and the two longitudinal vessels are the same as in my Boltenia australiensis . In general form, composition, and appearance the spicule is like that of the Alcyonaria, while it more particularly resembles that from the stem of Boltenia reniformis , as represented by the late Prof. Quekett (‘Lec ­ tures on Histology,’ 1852, p. 264, fig. 148); that is, consist ­ ing in its most perfect state of a short thick shaft, terminated at each end by a rosette of five globular tubercles arranged quincuncially, the whole about 8 by 7-6000ths in. in greatest dimensions.