SOME NEW AND RARE CEPHALOPODA. 107 
this, and Sepia, are tied down or inserted at the internal surface of the base of each 
arm ; the intermediate portions of the lip form an internal and smaller uniting web, of 
which the portions between the third and fourth pair of arms are the widest. With 
respect to the outer web, we may, I think, justly infer, that since in the Octopodous 
tribe of Cephalopods it forms, in the total absence of the mantle-fins, the sole organ of 
swimming, so here it is developed, though in an inferior degree, to compensate in some 
measure for the feeble condition of the terminal fins ; and we may consequently conclude 
that the locomotion of the Cranchi@ in the watery element is principally in the retro- 
grade direction. 
The brachial suckers are pedunculate, and arranged in a double alternate series along 
the margin of each arm; the interspace is wider than usual, and from the semitrans- 
parency of the part in this small Cephalopod, the gangliated nerve which supplies the 
part was beautifully distinct, as seen by transmitted light under the lens, running along 
the centre of this part. The tentacles are relatively thicker than in any other Decapo- 
dous Cephalopod, forming a remarkable contrast to the extremely slender and elongated 
ones in the genus Loligopsis. The suckers, which are irregularly clustered at the slightly 
expanded extremities, are much smaller than those of the arms, but are also peduncu- 
lated ; the extremities of the tentacles are fringed on both sides with a thin entire narrow 
membrane : the nerve which runs along the middle of these parts is a simple opake chord 
where it is lodged in the stem, but becomes enlarged and knotty at the acetabuliferous 
extremity. 
The mandibles were protruded in our specimen to an extent which seemed to have 
been produced by accidental compression. They were composed of a thin horny sub- 
stance, of a brown colour, at the sharp-pointed extremities, and along the smooth tren- 
chant margins, but elsewhere colourless. The jaws were surrounded by a thick, plicated, 
but not papillose, internal lip, and by the outer thin membranous fold above mentioned. 
The infundibulum was of small size, and projected in the usual situation from the man- 
tle ; it differed from the same part in the genus Loligo, in being obliquely truncate at the 
extremity, in such a direction that the dorsal parietes were folded down at this part, 
and overlapped the ventral, as shown in the magnified figure. On laying open the ventral 
parietes of the mantle, we found that the base of the funnel was not articulated by 
lateral moveable ball and socket joints to the internal surface of the ventro-lateral parts 
of the mantle, but that its ventral parietes became expanded, thin, and transparent, and 
were inserted into, and became continuous with, the corresponding parts of the mantle. 
According to Rathké, the funnel is attached in a similar manner by the adhesion of the 
ventro-lateral parts of its bases to the corresponding parts of the mantle in the genus 
Loligopsis. In all the other genera of Decapodous Cephalopods the funnel is articulated 
to the mantle at the exterior part of its base by two enarthrodial joints, the projection 
being on the mantle, and the socket on the funnel; both parts of the joint are com- 
posed of cartilage, covered by a fine smooth synovial membrane; but here we have a 
