196 MANUAL OF THE MOLLUSCA. 



by a small semilunar veil ; mouth with horny jaws ; gills papillose, on ridges 

 down the sides of the back, and round the head in front ; vent dorsal. 



ANTIOPA, A. and H. 



Type, A. splendida, A. and H. Syn. Janus, Verany. 



Animal ovate-oblong, pointed behind ; dorsal tentacles lamellated, united 

 at the base by an arched crest ; head with a small veil and two labial tenta- 

 cles ; gills ovate, placed along the lateral ridges of the back and continuous 

 above the head ; vent central, posterior, sexual orifice at the right side ; lin- 

 gual teeth numerous. ? 



Distr. Brit. Medit 



HERM.EA, Loven. 



Type, H. bifida, PL XIII. fig. 17. Norway, Brit. 



Animal elongated, tentacles folded longitudinally; giDs numerous, papil- 

 lose, arranged down the sides of the back ; sexual orifice below right tenta- 

 cles ; vent dorsal, or sub-lateral, anterior. 



ALDERIA, Allman. 



Etym. Named after Joshua Alder, one of the authors of the Monograph 

 on the British Nudibranchiate Mollusca. 



Type, A. modesta, PL XIII. fig. 18. Norway, S. Ireland and S. Wales. 



Animal oblong, without tentacles ; head lobed at the sides ; gills papil- 

 lose, arranged down the sides of the back ; vent dorsal, posterior, 



? Stiliger (ornatus) Ehrenberg ; Red Sea. Vent dorsal, anterior. 



FAMILY IX. PHYLLIRHOIDJS. 



Animal pelagic, foot-less (apodal), compressed, swimming freely with a 

 fin-like tail ; tentacles 2, dorsal ; no branchiae ; lingual teeth in a single 

 series ; stomach furnished with elongated co3ca ; orifices on the right side ; 

 sexes united. 



PHYLLIRHOE, Peron and Lesueur. 



Etym. Phyllon, a leaf, rhoe, the wave. Syn. Eurydice, Esch. 



Type, P. bucephala, Peron. Distr. 6 sp. Medit. Moluccas, Pacific. 



Animal translucent, fusiform, with a lobed tail ; muzzle round, truncated ; 

 jaws horny; lingual teeth 3.0. 3.; tentacles long and slender, with short 

 sheaths ; intromittent organ long, bifid. 



FAMILY X 



Animal shell-less, limaciform, with no distinct mantle or breathing organ ; 

 respiration performed by the ciliated surface of the body ; mouth armed with 

 a single series of lingual teeth ; stomach central, vent median, sub-central ; 

 hepatic organs branched, extending the length of the body and opening into 

 the sides of the stomach ; sexes united ; male and ovarian orifices below the 



