1880.] NATURAL SCIENCES OF PHILADELPHIA. 99 



phoria with about twenty leaves. The branchial leaves stronjr, (in both 

 individuals) eiglit in number, the two hindermost separateil by a narrow 

 crest, which rises into a larger papilla ; before this the anal papilla, 

 covered with some papilloe, at its right side is the r^nal pore ; on the 

 space before it were several smaller papilla?. The under side of the 

 free margin of the mantle (about 2.0 mm, broad) smooth. The head 

 large, the tentacles short. The genital opening a rather large, cres- 

 centic orifice. The foot rounded behind. 



The peritoneum was richly dotted on the back with brownish-red. 



The central nervous system nearly quite as in Ac. pilosa; the 

 proximal olfactory ganglia of oval form, true distal ones could not be 

 detected in the root of the rhinophoria, but only a fusiform swelling of 

 the nerve, with scattered nervous cells. The subcerebral and pedal 

 commissures connected, the visceral isolated. The buccal ganglia 

 larger than the olfactory, of oval form, connected by a commissure 

 nearly as long as each ganglion ; the gastro oesophageal ganglia de- 

 veloped on the side of the nerve, which is a little longer than the 

 ganglion, and in size about one-fifth of the former ; the contents one 

 very large cell, three or four smaller and several quite small ones. 

 On the upper part of the penis the large ganglion genitale, of about 

 the diameter of 0,3 mm., rounded, partly covered with black pigment 

 consisting of only rather small cells ; in the first parts of the nerves 

 given off from the ganglion, one or two rows of nervous cells of the 

 same kind as in the ganglion. 



The eyes with black pigment, yellow lens ; the optic nerve rather 

 long. As chalk-white points the otocysts were situated on the hinder 

 part of the cerebral ganglia, where they touched the pedal ones ; they 

 were filled with solid, yellowish otokonia of about the usual form and 

 size, but, in both respects, rather irregular. In the leaves of the 

 rhinophoria no spicula. In the margin of the mantle and of the foot 

 almost no spicula at all, but everywhere in the skin, especially on the 

 back and the papilla, were an enormous quantity of large and small 

 glandular openings. In the interstitial connective tissue were hardly 

 any calcified cells at all. 



The mouth-tube was about 2.3 ram. long, wide, with a glandular belt 

 on the outside, not closed below ; on the inside lined with a yellowish 

 cuticula. The bulbus pharyngeus strong, about 4.0 mm. long, and 

 the sheath of the radula projecting nearly 10 mm. from the posterior 

 part of the under side, directed straight backwards or downwards ; the 

 height (through the buccal crop) 4.0 mm., the breadth 2.5 mm. The 



