108 AMERICAN MARINE CONCIIOLOGY. 



Synopsis of Genera. 

 SuMimily Doridin^. 



Body depressed, rounded above ; mautle couvex, large, simple, cover- 

 ing the head and foot. 

 Tentacles dorsal, subclavate, laminated, retractile within a cavity ; 

 gills arborescent, retractile ; vent in the centre of the gills. 



Doris, Linnneus. 

 Body covered with an ample, smooth mantle, oval, convex ; dorsal 

 tentacles retractile, without sheaths ; head prominent, the lateral 

 angles prolonged anteriorly as short oval palpi or tentacles ; foot 

 broad, cordate ; branchiae posterior, in the groove between the man- 

 tle and foot. Doridella, Verrill, 



Subfamily Polycerin.e. 



Body elongate, sul)angular; mantle indistinct. 



Body smooth or tubcrculated ; tentacles clavate, pectinate, non-re- 

 tractile, without sheaths ; a frontal veil with simple processes on the 

 head ; gills with two or more lateral appendages. 



PoLTCERA, Cuvier. 



Genus DOBIS, Linnieus. 

 Syst. Nat., edit. x. GaS. 1758. 



The branchial plumes form an elaborate coronal around the 

 vent, which, viewed with a common lens in a A'essel of water, 

 forms, when fully expanded, a beautiful object. The surface of 

 the mantle is either smooth or tubercular, and the sheaths of the 

 tentacles are often crenate on their margins. 



1. D. BiLAMELLATA, Linnreus. Fig. 220. 



Syst. Nat., edit. xii. 1083. 1707. 

 Doris fusca, Muller, Zool. Dan. Prodr. 229. 1780. 

 Doris verrucosa, Pennant, Brit. Zool., iv. 43, t. 21, f. 23. 1777. 

 Doris vuhjaris, Leach, Syn. Moll. Gr. Brit. 19. 

 Doris Elf ortiana. Leach, Ibid., 20, t. 7, f. 1. 

 Doris ajfinis, Thompson, Ann. Nat. Hist., v. 85. 

 Doris liturata, Beck, IM oiler, Ind. Moll. Grcfnl., 5. 

 Doris obvelata, Bouchard, Cat. Moll. Boul., 42. 

 Doris coi-onata, Agassiz, Proc. Bost. Soc. Nat. Hist., iii. 191. 



Body elliptical, covered with pestle-shaped papilla?, whitish 

 varied with rusty brown or flesh-color, and opaque white; brancliire 

 twenty to twent^^-ftve, long, linear, simply pinnate, arranged trans- 

 versely in an oval, including several tubercles. 



Length about an inch, widtli half an inch. 



New England to Greenland, N. Europe. 



