108 AMERICAN MARINE CONCIIOLOGY. 



Synopsis of Genera. 

 Subfamily Doridin.e. 



Body depressed, rounded above ; mantle convex, 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. 



Dokis, Linnaeus. 

 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. 



Sul (family Polycerin.e. 



Body elongate, subangular; mantle indistinct. 



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

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

 head ; gills with two or more lateral appendages. 



Polycera, Cuvicr. 



Genus DORIS, Linnaeus. 

 Syst. Nat., edit. x. 653. 1758. 



The branchial plumes form an elaborate coronal ardund the 

 vent, which, viewed with a common lens in a vessel of water, 

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

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

 tentacles are often cremate on their margins. 



1. D. BILAMELLATA, Linnreus. Fi^. 220. 



Syst. Nat., edit. xii. 1083. 1767. 

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

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

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

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

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

 Doris liturata, Beck, Moller, Ind. Moll. Grcenl., 5. 

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

 Doris coronata, Agassiz, Proc. Bost. Soc. Nat. Hist., iii. 191. 



Body elliptical, covered with pestle-shaped papillae, whitish 

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

 twenty to twenty-live, long, linear, simpl} T pinnate, arranged trans- 

 versely in an oval, including several tubercles. 



Length about an inch, width half an inch. 



JV< w England to Greenland, N. Europe. 



