1879.] NATURAL SCIENCES OF PHILADELPHIA. 121 



a slight tinge of olive. The rhinophoria and branchiae of deeper 

 yellow. It was about 28.0 mm. long, 13 mm. broad, and 7.0 

 mm. high; the foot 7.0 and the free mantle edge 3.0 mm. broad. 

 The rhinophoria 2.5 mm. and the branchial leaflets 3.5 mm. high. 

 It was of rather depressed elongate form ; the mantle margin 

 rather broad. The back covered all over with rather small com- 

 pressed or rounded densely set tubercles, which often coalesced, 

 forming short longitudinal folds. These nearly disappeared at 

 the margin of the mantle. The rhinophorial orifices situated 

 rather forward with several tubercles on their margins, the club 

 of the rhinophoria with twelve to fifteen large and very oblique 

 leaves. The opening of the branchial cavity (the branchial leaves 

 retracted) was a longitudinal slit of about 4 mm. in length, and 

 rather narrow; the margin of it with tubercles of the usual kind. 

 The" branchial leaves nine in number, four lateral pairs and one 

 anterior unpaired, tripinnate. The anal tube low, with two 

 (lateral) lips (fig. 19); the renal pore in front of and at its right 

 side. The outer mouth a small longitudinal slit; the tentacles 

 very small, with a furrow at the upper part of their outer margin. 

 The under side of the mantle edge even ; a small deep groove for 

 the head. The sides of the body rather low; the genital opening 

 round, with at least two openings in its depth. The foot rounded 

 at the fore end with traces of a fine furrow, the posterior end 

 somewhat pointed. 



The intestines where visible through the skin. The peritoneum 

 colorless, nearly without spicula. 



The central nervous system showed the cerebral and the vis- 

 ceral ganglia very distinct; the cerebral short, reniform, a little 

 broader in the anterior part, a little larger than the buccal, bulbi- 

 form, short-stalked; the optic ganglia scarcely equal to one-tenth 

 of the size of the latter; the optic nerve short. The visceral 

 ganglia short, pyriform ; on the under side of the right hand are 

 a short-stalked genital ganglion, intermediate in size between 

 the optic and olfactory ganglia. The pedal ganglia nearly per- 

 pendicular oh the under side of and a little smaller than the vis- 

 ceral. The commissures rather short, the visceral nearly free 

 from the broad subcerebro-pedal. 



The buccal ganglia rounded and connected by an extremely 

 short commissure. The gastro-oesophageal short stalked, ovoid, 

 9 



