248 SCIENTIFIC RESULTS OF THE 
phoria with about twenty leaves. The branchial leaves strong, (in both 
individuals) eight in number, the two hindermost separated by a narrow 
crest, which rises into a larger papilla; before this the anal papilla, 
covered with some papilla, at its-‘right side is the renal pore; on the 
space before it were several smaller papillz. 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-cesophageal 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 mm, 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 1.0 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 2.5mm. The 
