108 MR. OWEN'S DESCRIPTIONS OF 



singular exception to all other enarthrodial joints, for the synovial membrane does not 

 form a shut sac, but is continuous with the mucous membrane lining the interior of the 

 mantle. The convex cartilage is of an oval form in the Cuttle-fish ; in the Calamaries 

 (Loligo) it forms an elongated ridge ; in the genus Onychoteuthis the articular ridges 

 commence at the anterior margin of the mantle, and extend one third of the way down 

 the sac, being formed by two thin lateral cartilaginous lamina, placed rather towards the 

 ventral aspect of the mantle ; an elevated groove in the corresponding side of the funnel 

 plays upon each of these ridges ; but in the genus Loligopsis the sides of the funnel adhere 

 to the corresponding cartilaginous lamincB ; these which have been supposed to be ano- 

 malous and peculiar to that genus differ from the lateral cartilages of other Decapodous 

 Cephalopods only in their greater length and tuberculated form. In the Cranchia these 

 cartilages are entirely wanting, as in the Octopodous Dibranchiata. ' 



With respect to the anatomy of the Cranchia, I can only state that it possesses two 

 gills, which are provided with branchial ventricles, but that these are without fleshy 

 appendages ; and that it has two large inferior salivary glands. The decomposed state 

 of the digestive and generative viscera in the present specimen prevented any satisfac- 

 tory observations being made upon them. 



From the preceding description it will be evident that the genus Cranchia differs from 

 Loligo in particulars of sufficient importance to justify a generic separation, and that in 

 the attachment of the funnel to the mantle, and in the absence of appendages to the 

 branchial ventricles, it is allied to the genus Loligopsis, which it also resembles in the 

 rounded form and terminal position of the fins. From this genus, however, it is distin- 

 guished by the adhesion of the mantle to the head, by the presence of the infundibular 

 valve, by the comparative strength and shortness of the tentacles, and by the webs 

 extended betw^een the first, second, and third arms. 



The four specimens of the small species of Loligo, which is the second on the list of 

 Mr. Bennett's Cephalopods, belong to a species hitherto undescribed, and which, from 

 the peculiar breadth of the head, I propose to call laticeps'. The diminutive size of these 

 specimens, the largest of which measures only 1^ inch from the extremity of the mantle 

 to the end of the outstretched tentacle, suggested at first a denomination indicative of 

 that particular ; but when we reflect that in other genera, as Octopus, there have been 

 found species of still smaller dimensions than the one now described, it may ultimately 

 be discovered, even if adult, to be not the smallest of its genus. Mr. Bennett gives the 

 following note relative to the capture of these small Calamaries: — "April 5th, fine 

 weather ; wind east by north ; light and moderate breezes ; thermometer 68° to 72°., lat. 

 29° 17' north ; longitude 46° 57' w^est : at noon, among a mass of ' Sargasso weed,' took, 

 in my towing net, small Sepice of a fine purple colour with dark red spots." 



' Pl.XXI.fie-s. 6— 11. 



