OCR Text |
Show 1883.] SPECIES OF HOLOTHUROIDEA. 61 which 6 are internal to the rest; retractors fairly stout, very short. Polian vesicles two, rather short, irregular in shape. Genital tubes numerous, of some length, extending back as far as the middle of the body; the last division may have four terminal branches. The calcareous ring is remarkably well developed, the radial pieces being very stout and broad, a little hollowed externally, with the backwardly directed processes short and feeble; the proximal end of the interradial piece is constricted (fig. 5 b). The only calcareous bodies that were detected either in the skin, which is not remarkably thick, or in the walls of the suckers were stoutish discoidal bodies the perforations in which may be rare and small. They are present in large numbers. Length 80 millim., breadth about 50, length of calcareous ring 14, Polian vesicle 10. Colour-ground-colour white, the trivial surface with blotches of dark brown ; lighter brown spots, lines, ort patches may be seen on tbe bivium. Hab. Bay of Honduras. Collected by G. E. Dobson, M.B., and presented by him to the British Museum. I have the pleasure of associating with this species the name of its discoverer, a name well known to all zoologists. STEREODERMA MURRAYI. (Plate XV. figs. 6, 6 a, 6 b.) I have been for some time acquainted with a second species of this remarkably firm-bodied genus, an account of which will appear in the forthcoming report on the zoological collections made by H.M.S. 'Alert.' It has fortunately happened that that new species is particularly well represented; and the supply of specimens has enabled me to note that there are considerable variations in the arrangement of the suckers in the " double row," and that the regularity of this may become considerably obscured. Fortified by these examples, I have less hesitation than I should otherwise have had in associating with this genus a single, rather small specimen from the seas of Kurrachee, which the British Museum owes to Mr. Murray. I venture to associate the name of this energetic curator with this interesting new species. Tentacles small, dark ; retractors exceedingly delicate, though with a broad base of origin; Polian vesicle very long and narrow ; oesophagus covered with a calcareous plating, much as in Thyone sacellus (see Selenka, Zeitschr. f. wiss. Zool. xvii. pi. xx. fig. 115). (Plate X V . fig. 6 b.) Integument very thick, and filled with strong-walled firm corpuscles, not so thick, however, as in S. unisemita, or so large as in S. validum. Skin white in colour, the double row of the suckers only well developed in the anterior third of the body, but better developed behind than in the middle. About 30 millim. long and 11 wide; of the same, or nearly the same, width along its whole extent. Hab. Kurrachee. In exchange with the Kurrachee Museum. |