110 AMERICAN MARINE CONCHOLOGY. 
white minute tubercles; white, with a row of irregular bright- 
yellow spots down each side; branchial plumes ten, small, pin- 
nated. 
Length 15, breadth 12 mill. 
New England, N. Europe. 
6. D..GRIsEA, Stimpson. Fig. 225. 
Gould, Invert. Mass., 232, t. 20, f. 292, 295. 1870. 
Body oblong-oval, covered with blunt processes tipped with 
stellate clusters of spiculze; branchial plumes short, yellowish, 
arranged in a circle around a dark bristle; head short, broad, an- 
gular. 
Length 13, breadth 9 mill. 
Massachusetts. 
Verrill (Am. Journ. Sci., 1. 408, 1870) places this species in the 
genus Onchidoris. 
4. D. pirripA, Verrill. 
Am. Journ. Sci., 1. 406. 1870. 
Broadly oval, widest anteriorly, back very convex, mantle 
covered with pointed. papilla. Tentacles rather long, thickest in 
middle, the outer half strongly plicated, but with a smooth tip, 
the base surrounded by small” papillae. Dark purple-brown, with 
white spots; the edges and tips of the gills yellow. 
Length 1 inch, breadth } inch. 
Eastport, Maine. 
Genus DORIDELLA, Verrill. 
’ : Am. Journ. Sci., 1. 408. 1870. 
1. D. opscura, Verrill. Fig. 226. 
Am. Journ. Sci., 1. 408, f. 2. 1870. 
Broadly oval; back convex, smooth. Foot broad, cordate in 
front. Oval. disk broad, emarginate or with concave outline in 
front; the angles somewhat produced, forming short, tentacle-like 
organs. Dorsal tentacles small, stout, retractile. Color blackish, 
lighter towards the edge, as if covered with nearly confluent black 
spots; foot, oral disk, and dorsal tentacles white ; the central part 
of the body, beneath, bright yellow. 
Length 7.5, breadth 5 mill. 
New Haven, Conn. 
