The Genus *‘ Paraplysia”’ with Description of a New Species. 123 
At their anterior extremity they are separated from each other by 
a somewhat narrow space and at their posterior extremity by a 
space of about the same extent. In the former space lie the two 
rhinophora, and in the latter is the siphonal prolongation of the 
mantle. This latter space is much more marked than in A. depilans, 
and shows no indication whatever of any continuity between the 
ends of the pleuropodia. 
The anterior tentacles are well developed and ear-shaped, being 
widely separated and situated at the ends of the broad frontal region. 
The posterior tentacles or rhinophora are small, conical in shape, 
and situated directly between the anterior ends of the pleuropodia. 
The bases of the tentacles are in contact with each other and that 
of the left tentacle with the left pleuropodial extremity. The right 
tentacle is only separated from the right pleuropodial by the genital 
furrow. 
The colouration of the tentacles is that of the body generally, with 
the exception of the extreme tips, which are of a yellow colour. 
The genital opening (PI. XVI. Fig. 3, g. 0.)is situated a little posterior 
to the middle point of the body, and is just covered by the mantle 
(Pl. XVI. Fig. 3, m.) under the anterior free edge of which it lies. The 
mantle itself, which can be completely covered by the pleuropodia, is 
thus situated in the posterior half of the body, and occupies about half 
of this region (excluding that part which is prolonged as a siphon). 
In the centre of the mantle appears a minute shell aperture. The 
siphon is well marked, being about half of the length of the mantle 
proper, but does not extending to the posterior extremity of the foot. 
The gill (Pl. XVI. Fig. 3, g.) is completely covered by the mantle 
(Pl. XVI. Fig. 3, m.), in which is embedded a shell completely devoid 
of any carbonate of lime (Fig. 4). 
The osphradium is not readily distinguished externally, and lies 
under the anterior extremity of the gill where it joins the body. 
The opaline gland (Fig. 3, o. gl.) is multiple and well developed, 
lying in the angle between the right pleuropodia and the body and 
extending from a point a little posterior to the genital opening to the 
free extremity of the gill. 
The visceral mass is not distinctly separated from the foot pos- 
teriorly, but forms a sharp angle with it. The anus, however, being 
situated at some distance from the base of the siphon, at about 
a quarter of its length, a part of the rectum may be regarded as 
separated from the body—an approach to the condition so charac- 
teristic of P. Mowhott. 
Colowration.—The body generally is of a dark olive-green, scattered 
irregularly in large angular patches, which are separated by fine 
