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Show 1 9 0 4 .] FROM EAST AFRICA AND ZANZIBAR. 2 8 9 The radula consists of a single series of teeth of the form usual in the genus, with a moderately large central cusp and six denticles on each side, of which the innermost and outermost are the smallest and the median the largest. The jaws bear a single series of 35 rather irregular denticles. The verge is armed with spines. This appears to be a new species of Facelina, but I have not had an opportunity of seeing the description of F. cyanella (Couth.), which Bergh refers to this genus with a query. P h yllodesm ium h y a l in u m Ehrenb. [Elirenberg, Symbolse Physic*, series prima, 1831 ; Bergh, " Anatomisk Undersogelse af Ph. liyalinum" Naturhist. Foren. Vidensk. Meddelelser, I860.] One specimen dredged in about 10 fathoms near Wasin. The notes on the living animal are as follows:-" About one inch long. Body semiopaque, pure white. Rhinophores and tentacles ditto. Rhinophores slightly annulated, shorter than the tentacles. Cerata very long and opaque, so that the liver is not visible ; whitish violet in colour ; their upper halves and the whole length of the sides are covered with low rounded projections, between which dark-brown pigment is found. The first groups of cerata are almost at the side of the rhinophores, and consist of only two cerata on each side. The remaining cerata are set in seven pairs of clumps of four each, and there is a space between the second and third pairs of clumps. The cerata are somewhat flattened." The preserved specimen is 10\5 mm. long and 3 broad, with a thread-like tail. Relatively to the size of the animal, the cerata are enormous, the largest being 8 mm. long. They are flattened, rather convex on the outer and concave on the inner face. The edge all round is marked by a line of knobs, which are, however, more numerous at the top than at the bottom. On the outer side the whole surface of the upper half is covered with similar knobs. On the inner side the surface is mainly smooth except at the edges, but at the very top there are a few knobs. The cerata are largest on the inside, and gradually decrease outwards. The smallest appear to have no knobs. The larger are easily detached, and hence the arrangement of groups was not easy to see in the preserved specimen, but it appeared to have been as described in the notes on the living animal. The rhinophores are short and thick, set close together, and annulate. The tentacles are longish and curved. The foot is grooved anteriorly, and produced into moderately long but not conspicuous tentacular angles. The anal papilla is latero-dorsal, just behind the rather large pericardial prominence. The genital openings are under the rhinophores. The jaws bear five or six coarse denticles, of which three are very large indeed, the others smaller. The radula consists ot sixteen colourless teeth, bearing between 30 and 40 denticles on each side. The shape is much as in Bergh's plates (I. c.), but the denticles are rather longer. P roc. Z ool. Soc.- 1904, V o l . II. No. XIX. 19 |
