MR. A. HANCOCK ON THE ANATOMY OF DORIDOPSIS. 193 
in the interior, exhibiting only the three or four peculiar longitudinal areas above de- 
scribed in that species. Here, likewise, there is no armature whatever, either in the 
form of tongue, jaws, or collar; and it may be stated that I have examined with great 
care the oral organ of six or seven species with the same negative result. The intestine 
of D. nigra is a short constricted tube (Pl. XV. fig. 2m, & Pl. XVI. fig. 1 g), and passes 
backwards at once on reaching the surface of the liver, which is large, elongated, hol- 
lowed in front, bifid behind, and of a brownish-yellow hue. 
In D. atromaculata the proboscis is quite slender, and tapers imperceptibly into the 
erop or anterior stomach, which is well developed. No external head is visible in this 
species, which in other respects is abnormal. The oral aperture is minute, and is 
situated immediately in front of the margin of the foot, differing in this respect from 
that of all the other species, in which the mouth invariably opens through the anterior 
margin or immediately behind it. In them, however, this margin seems to be formed 
by a lamina similar to that so common in Doris; while in the species before us there 
is no appearance of such lamina. 
The alimentary tube of D. miniata is in some respects a little modified. The head 
is small and inconspicuous; the mouth is very minute, and opens in the usual way in a 
cleft in the anterior margin of the foot. The proboscis, in one of the individuals examined, 
Was exserted, and was found to be long and slender. The inner or posterior portion is 
not dilated, but forms, in continuation with the part corresponding to the crop or ante- 
rior stomach, a long, constricted cesophagus, which extends nearly from one end of the 
body to the other, reaching, in fact, nearly to the posterior extremity of the liver. The 
intestine passes from the upper surface of that viscus, and is considerably dilated at 
first; it stretches for some little distance forwards, and then turns to the right and, 
suddenly bending backwards, runs beneath the pericardium much reduced in calibre and, 
ends in an anal nipple situated not, as usual, in the centre of the branchial circle, but at 
the left side, and. close to the base of the plumes, there being two before and three be- 
hind a transverse line drawn through it. 
Reproductive System. —The generative organs are arranged upon the same plan as in 
other Nudibranchs ; they are hermaphrodite, being composed of male, female, and andro- 
synous parts, differing in no material manner from those in Doris. 
The ovary (Pl. XV. fig. 1%) is lobulated, and is spread over the anterior of the liver; all 
the other parts ( 7, j) are placed well forward on the right side, and extend backwards 
about one-third the length of the body. Between the mantle and foot there is a common 
orifice that leads into a very shallow vestibule, through the inner wall of which are three 
Openings, one for the exsertion df the penis, another leading to the androgynous organs, 
and the third to the female channel. 
The male and androgynous apertures are placed in front of the female orifice, and are 
closely associated together, the male being anterior. The penis (Pl. XVIII. fig. 4b) is 
Very slender and linear, much more so than in any Doris I have examined. The glandular 
Ae seing the penis with the oviduct is composed of two portions, one much stouter 
i the other. The delicate or outer portion (fig. 2 c) is connected with the root of the 
penis (5), ang is much longer than the other (d), which, however, is of considerable 
