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Show 1904.] FROM EAST AFRICA AND ZANZIBAR. 1 0 3 One specimen from the East Coast of Zanzibar. Notes on living animal: " Rhinophore bearers very large indeed; colour whitish, netted with orange." The alcoholic specimen is more stoutly built than those already described. It is somewhat bent, and would be at least 30 millimetres long if stretched out. It is 5 mm. high and 4‘5 broad. The rhinophore-sheaths are 8 mm. high, the cerata 5'5. The tentacular process consists of 11 fairly long digits, all distinct and none of them merely tubercles. The large rhinophores bear 7 digits, three in front quite separate, and five behind united at the base. Posteriorly there are traces of what may be a crest. Behind the rhinophore-sheaths are three pairs of cerata, somewhat resembling those of Doto in general appearance. They all bear three digits, above which rises the top, covered with knobs. They also all bear three stout branchiae, two of which are visible from the outer side and are protected by the digits. The jaws and labial armature are much as usual; the former have blunt indentations on the edge. The radula consists of 27 rows with a maximum formula of 16.1.16. In the median tooth the central cusp is rather longer than depicted by Bergh, and there are 10-12 denticles and ridges on each side. The second stomach and the prseputium are armed with black spines as described by Bergh (Chall. Rep. I. c.). The liver sends branches into all the cerata except the right-hand member of the first pair, but not into the rhinophore-sheaths. I am somewhat doubtful if this is really Bergh's B. excepta: there are differences in the arrangement of the cerata and branchiae and the rhinophore-sheaths are relatively much larger. On the other hand, the two specimens examined by Bergh did not agree in details, and the present animal possesses more or less the characters common to them. B ornella s im p l e x , sp. n. (Plate IV. fig. 5 c.) One specimen from Chuaka, East Coast of Zanzibar. The following are the notes on the living animal:-" Very like B. digitata, but a distinct species. Anterior tentacles short and simple. Whole coloration transparent, so that the walls of the heart are distinctly visible. No opaque white or orange rings on tips of cerata, but an orange network on the back and a row of opaque white dots on the sides. Eyes not visible. Length 12 millimetres." Superficially the alcoholic specimen looks much like B. excepta as described above and has the same Boto-Yike cerata, but it is at once distinguished by having on each side of the mouth not the usual tentacular rosette, but a single simple tubercle. The left tubercle is larger than the right. The rhinophore-sheaths bear six short digitations and a larger rounded knob behind. There are four pairs of cerata, of which the hindmost are simple warts. The others are similarly constructed, though the third pair are smaller than the first two. Each is divided into four knob-like |