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 Uctopodous 

 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 Cranchics 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 supphes 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 Becapo- 

 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, phcated, 

 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 obhquely 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 bail 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 Rathke, 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 



