GASTEROPODA. 329 



Suh-gmus. Oncidoris (Bl ?). D. bilamellata, Jolinst. Back 

 elevated, tuberculose ; gills non-retractile ; oral tentacles fused 

 into a veil ; buccal mass with, a gizzard-like appendage ; lingual 

 teeth 2 in each row. (A. and H.) 



D. scutigera {VilUersia), D'Orbigny, Eochelle ; has the mantle 

 more than usually strengthened with calcareous spicula. 



Distribution, 100 species. 



The Dorids vary in length from 3 lines to more than 3 inches ; 

 they feed on zoophytes and sponges, and are most plentiful on 

 rocky coasts, near low water, but range as low as 25 fathoms. 

 They occur in all seas, from Norway to the Pacific. 



HEPTABEAisrcHUS, A. Adams. 



Mantle without a longitudinal ridge on the back; 7 gills 

 arranged in a semicircle ; oral tentacles star- shaped. 



Hexabranchtjs, Ehrenberg. 



Same as last, but with 6 gills arranged in a cross on the hinder 

 part of the body ; oral tentacles notched. 



Atagema, Grube. 



Mantle with longitudinal ridge on the back ; tentacles clavate, 

 retractile ; gills very small. 



Distribution, 1 species. New Zealand. 



ACTINOCYCLIJS, Ehrenberg. 



Animal ovate ; back naked ; gills very plumose. 

 Distribution, 7 species. East Africa and South Europe. 



Cheomodoeis. 



Animal almost quadrangular; back naked; feathery gills 

 arranged lineally. 



Distribution, 1 species. East India. 



AsTEEOisroTUS, Ehrenberg. 



Animal ovate : the apertures for the gills and tentacles almost 

 closed. 



Distribution, 2 species. East Africa and South Europe. 



Glossodoeis, Ehrenberg. 



Synonym, Pterodoris, Eb. 



Tentacles retractile; back covered with unequal cylindrical 

 processes ; a thread-like process on each side of the fore part of 

 the foot. 



Distribution, 1 sppciQs. igast India and West America. 



