NOTES ON A COLT.ECTION OF CAT.IFORNIAN NUDIBRANCHS. 39 



covered with black-tii)i)e(l papillae, among which, especially near the margin, 

 are some rather larger colourless papillae. The black tips of the papillae, 

 and the black border round the mantle are very vivid and distinct. The 

 length is i 2 niillim.; the breadth 10 millim., and the maximum height 5 millim. 

 'l"he rhinophores are retracted, and the pockets not very easy to see as they 

 are surrounded by tubercles, some colourless, some tipped with black. The 

 branchiae are pinkish-grey, not ample, bi — and in places tripinnate. They 

 are five in number, but in a vacant place on the right side of the circuit are 

 some rudimentary plumes, suggesting that the full number is six. Though 

 there is no pocket into which the branchiae can be retracted, the branchial 

 area is differentiated from the rest of the back. It is of a deeper pink colour, 

 bears very few tubercles, and in parts, though not everywhere, is surrounded 

 by a rim formed by the union of some of the dorsal papillae. This is pro- 

 bably the same arrangement as that described by Abraham for Calycidoris. 

 The anal papilla is central. The foot (9 millim. x 6.5 millim.) is broad and 

 rather abruptly pointed behind. The anterior margin is straight. The head 

 is surrounded by a crescent-shaped veil about as wide as the foot, and pro- 

 longed into short horns on either side. The sides of the body, the margin of 

 the mantle, and the branchial area contain a fair number of spicules, but there 

 are none in the rest of the dorsal surface. They are brownish rods, bearing 

 many marks resembling joints and divisions, bent in various ways, but not 

 branched or thickened in the middle. 



The buccal mass is pinkish ; the ingluvies buccalis which is imbedded 

 in it is divided into two halves by a white stripe. The labial cuticle bears 

 two prominent thick folds. The labial armature is a band of mosaic consisting 

 of squarish blocks (Fig. 3), irregularly cleft (often quadrilid) at the top. 

 Below these clefts are a number of minute, hardly visible, prominences. The 

 formula of the narrow radula (Fig. 4), is 27 x 5 or 6. i. o. i. 5 or 6, the sixth 

 tooth being very often absent. The rhachis is quite bare; the innermost 

 teeth are much larger than the others, and of the shape usual in this genus. 

 They have a large base and bear about 5 denticles (sometimes with a few 

 smaller additional denticles) near the top of the hook. The other teeth are 

 much smaller and are almost covered by the broad base of the first tooth ; 

 they decrease in size outwards, and are cjuite smooth, but preserve something 

 of the hamate shape. 



The liver is large and greenish ; the greater part of it is covered with a 

 thick white layer, formed by the hermaphrodite gland. The mucous gland 

 is large, white and transparent. The spermatoduct is long and consists of 

 two parts, the upper soft, and the lower muscular ; this lower portion and the 

 verge are thickly covered with small, slightly hooked, transparent prominences. 

 The central nervous system is distinctly granulate. The pedal ganglia are 

 set below, and at the sides of the cerebru-pleural. The eyes are on rather 

 long stalks. 



