90 TETHYS—WEST AMERICAN. 
rior portion long, swimming lobes inserted rather far back. Buccal 
lobes flattened and folded as usual, black within the fold. Poste- 
rior tentacles rather near together, conic and slit above, black 
within the slit, situated somewhat nearer buccal lobes than swim- 
ming lobes. Swimming lobes short and not very ample, united for 
a short distance behind. Mantle provided with a central minute 
tube; concentrically wrinkled ; having an uncommonly long poste- 
rior excurrent siphon, the left lobe tongue-like and long. 
Genital pore in the usual position; genital groove long. Opaline 
gland opening by a single large orifice. 
Color “ pale gray or greenish, becoming purplish on the side, folds 
of mantle with scattered white specks, from which an irregular net- 
work of brown lines extends over the rest of its body, interspersed 
with large brown blotches. Inner surface of [swimming lobes] varied 
with alternating painted bars of white and dark brown interlocking 
together. Sole of foot black. Eyes very minute and black.” The 
alcoholic specimen before me is yellowish, finely netted and spotted 
all over the sides and back with black- brown, sole blackish ; mantle 
black-brown with large yellowish maculz ; inside of swimming lobes 
black-brown barred boldly with dirty yellowish, the dark bars 
branching at the upper edges of lobes. 
“Shell cartilaginous, translucent, trapezoidal, or hatchet-shaped, 
margins rounded, slightly convex above, the nucleus in old spec- 
imens distant from the posterior end or apex. Faint radiating lines 
diverging from the nucleus, crossed by an irregular net-work of 
darker lines, all ending abruptly at some distance from the margin, 
which has thus a wide, nearly transparent border. An accessory 
plate arises on the inner surface from the nucleus, nearly spatulate 
in form and slightly raised.” (Coop.). The shell of the specimen 
figured on my plate shows the essential features mentioned by 
Cooper, but the accessory plate projects squarely above the upper 
margin. ‘The minute, incurved apex is situated some distance with- 
in the margin, being 4 mill. below the upper edge in the specimen 
figured. 
Monterey to San Pedro, California. 
Aplysia (Neaplysia) californica J. G. Cooper, Proc. Cal. Acad- 
Nat. Sci. iii, 18638, p. 57, fig. 14—Neaplysia californica, J. G. 
Cooper, Geographical Catalogue of the Mollusca found west of the 
Rocky Mountains between lat. 33° and 49° N., no. 241, p. 14 (Geol. 
Surv. of Cal. 1867.) 
