258 SCIENTIFIC RESULTS OF THE 
foot 2.0 mm. The color of the animal whitish, that of the rhinophoria 
and the branchial leaves more yellow; the margin of the foot white. 
The form as usual. The head rounded, with a prominence on the 
upper lateral part; the mouth a vertical slit. The margin of the 
rhinophor-grooves plain. The stalk of the rhinophoria nearly as high 
as the club, cylindrical; the club rather flattened, with about fifteen 
leaves; before the rhinophoria a low transverse frontal veil with 
scarcely more than two prominences ; the veil continued backwards as 
a rather indistinct prominent line on each side of the smooth rounded 
back; the pericardial region a little prominent; behind the middle of 
the length of the back, the gill with six tripinnate leaves ina slight 
curve ; behind them the quite low anal nipple, and towards the right 
side the renal pore; behind the gill a little flattened space with a slight 
crest on each side with three papillae. The sides of the body rather 
high. In the region of the anterior angles of the foot the genital 
papilla with the everted penis (without its recurved point, 0.75 mm. 
high), and below it a folded lamella, the duct of the mucous gland. The 
foot rather narrow, of nearly the same breadth; the rounded anterior 
angles somewhat prominent; a fine furrow in the anterior margin. 
The intestines indistinctly appearing through the walls of the body. 
The peritoneum colorless, nearly without spicula. 
The central nervous system (fig. 1) very depressed; the cerebral 
ganglia of rounded-triangular form, a little larger than the more 
rounded visceral (fig. la); the pedal ones more pyriform, a little 
larger than the last; the (proximal) olfactory ganglia bulbiform, not 
quite as large as the buccal ones, which were (fig. 10) of rounded form, 
connected by a not very short commissure; the gastro-csophageal 
ganglia of about one-eighth of the size of the former, rounded.! ‘The 
three inferior (subcerebral, visceral, and pedal) commissures or at 
least the visceral one) free. 
The eyes (fig. 1) short-stalked, with black pigment and pale yellowish 
lens. The otocysts (fig. 1) in their usual place, very short-stalked, 
with about eighty otokonia of the ordinary kind. In the stalk of the 
rhinophoria some scattered yellowish thick spicula, of the same kind 
as in the skin of the back; none, on the contrary, in the leaves of the 
club. In the skin sume scattered, yellowish, thick, straight or curved 
spicula, mostly of about 0.15—0.3 mm. in length, and of the usual 
form. In the interstitial tissue very few larger spicula. | 
1-Tn the other species of Polycera I have examined, I never saw gastro- 
esophageal ganglia, nor any in Huplocamus or in Plocamopherus. 
