aASTEROPODA. 323 



base of tlie gill ,* head with two grooved tentacles, eyes at their 

 outer bases ; mouth armed with horny jaws and covered by a 

 broad veil with tentacular lobes. 



Distribution, 22 species. South America, Norway, Britain, 

 Mediterranean, Eed Sea, Ceylon. 



Suh-genus ? Fleurohranchoea, Meckel ; P. Meckellii, Leve, 

 Mediterranean. Synonym, Pleurobranchidium (maculatum), 

 Quoy, South Australia. Mantle-margin very narrow, not 

 concealing the gill ; dorsal tentacles ear-like, oral veil tentacu- 

 liform. 



PosTEROBRANCHJBA, D'Orbigny. 



Type, P. maculata, D'Orbigny. Coast of Chili. 



Animal shell-less ; oval, depressed, covered by a mantle 

 broader than the foot ; foot oblong, bilobed behind ; branchial 

 plume on the left side, projecting posteriorly; reproductive 

 orifice in front of gill, excretory behind ; proboscis covered by 

 a broad bilobed veil ; no dorsal tentacles. 



EuNCESTA, (Forbes) Hancock. 



Type, E. Hancocki, Porbes. 



Synonym, PPelta, Quatr. (not Beck). 



Animal minute, slug-like, with a distinct mantle ; eyes 

 sessile on the front part of the mantle; no tentacles; gills 3, 

 slightly plumose, placed with the vent on the right side, at the 

 hinder part of the back, beneath the mantle ; gizzard armed ; 

 reproductive organs on the right side. 



Distribution on Qonferv(R near high-water mark, Torbay. 



Neda, H. and A. Adams. 



Animal shell-less ; mouth terminating a proboscis, which is 

 long and thin; oral veil half-moon shaped, with two lateral 

 recurved tentacles. 



Distribution^ 1 species. South Europe. 



StJSAEiA, Griibe. 



Sliell small ; mantle tuberculated, extending well over both 

 head and foot ; notched in front. 



Distribution, 1 species. South Europe, 



Umbeella, Chemnitz. Chinese -umbrella shell. 



Type, U. umbellata, PL XIY., Pig. 18. 



Synonym, Acardo, Lam. Gastroplax, Bl. 



Shell, limpet-like, orbicular, depressed, marked by concontric 



