292 SIR C. ELIOT ON NUDIBRANCHS [NoV. 29, 



superficially, presents many points of diflference and is certainly 

 not a mere subgenus, as it is considered by Fischer (Manuel de 

 Conch, p. 343). Externally the chief difi'erence is that the foot 

 in Phyllohranchus is, as usual, an undivided surface, whereas in 

 Cyerce there are two distinct parts separated by a transverse 

 division. In Phylloh-anchus the buccal crop is long and twisted, 

 the vent lateral, and the teeth are preserved in a spiral. In 

 Cyerce the crop is flat and oval, the vent dorsal, and the teeth 

 are preserved in an irregular heap. The digestive organs also 

 present important differences, the chief of which is that whereas 

 in PhyllohrancJms (and in Caliphylla) the liver is ramified within 

 the dorsal papillae, in Cyerce it appears not to enter them at all 

 and to be wholly contained in the body- cavity. 



The function of the large buccal crop is obscure. It would 

 appear that, as a rule, this organ is only found when the radula 

 is vmiseriate (ascogiossan) or very narrow {Lamellidoris, Gonio- 

 doris, &c.), and when there are no jaws. On the other hand, its 

 presence xmder these conditions does not appear to be necessary 

 (e. g. Elysiadse and Hermseidfe), 



Phyllobranchus prasinus B. 



[Bergh, in S. R. Heft ii. pp. 52-87.] 



Fourteen specimens from Chuaka on the East Coast of Zanzibar, 

 mostly about 3 centimetres long, but two much larger, measuring- 

 over 5 centimetres in life. The animals were found at low tide. 

 The colour is described as transparent, with small green branching 

 lines on the cerata, giving on the whole an efiect of greyish 

 green. It was noticed that the cerata break ofi" easily when the 

 animal is disturbed, and retain the power of independent move- 

 ment for some time. 



The preserved specimens have kept their colour fairly well, but 

 many of them show a yellowish rim round the cerata, not men- 

 tioned in the description of the living animal or by Bergh. The 

 yellow spot on the cerata mentioned by Semper is not visible. 



The largest preserved specimen, which has lost nearly all its 

 papillse, is 47 mm. long and 14 broad. The head is separated 

 from the body by a sort of ridge, which descends and forms 

 lappets on each side of the mouth. The oral tentacles are un- 

 divided, about 7 mm. long, and slightly grooved. The rhinophores 

 are bifid ; the main branch measures 12-5 mm. and the side branch 

 5 "5. Both branches are grooved and also the common stem, but 

 less distinctly. The rhinophores seem larger than in Bergh's 

 specimens ; in one specimen only 25 mm. long they measure 

 12 mm. At the base of the rhinophores the black eyes are 

 clearly visible. The pericardial prominence lies 14 mm. from 

 the anterior margin. The opening for the penis is immediately 

 behind the right tentacle. The large female genital papilla is a 

 little further back on the right-hand side, under the rhinophores. 

 Still further back is the large, cup-shaped, anal papilla, under the 

 anterior end of the pericardial prominence. The foot has thin 



