124 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 3, 



slab. Neither of these indications call for a specific name ; future 

 explorations by their discoverer may bring to light more evidence of 

 the animal so indicated. iVlready much valuable knowledge of the 

 Vertebrate fossils of the Purbecks has been gained by the indefati- 

 gable researches and acute discernment of Mr. Brodie. 



3. Notice of a new species of an extinct genus o/'Dibran- 

 CHiATE Cephalopod {CoccoteutMs latipinnis) from the Upper 

 Oolitic Shales at Kimmeridge. By Prof. Owen, F.H.S., 

 F.G.S. &c. 



[Plate VIL] 



The subject of the present notice is the internal shell, * sepium' or 

 cuttle-bone of a large Dibranchiate Cephalopod, combining some of the 

 characters of that of the Cuttle (Sepia) with that of the Squid {Loligo, 

 Sepioteiithis, &c.). The specimen was discovered by W. R. Brodie, 

 Esq., at low-water-mark, in the shales at Kimmeridge, in a layer of 

 which it lies imbedded, with the dorsal surface exposed. It is 1 foot in 

 length, although the hinder pointed end is broken away, and 5^ inches 

 in breadth at its broadest part, about one-third from the hinder end ; 

 proportions which indicate the entire animal yielding it to have been 

 about a yard in length from the end of the outstretched arms (see 

 PI. VII.) . The sepium is slightly convex along the middle of the dorsal 

 surface, which is the one exposed, and this convexity is beset with hard 

 calcareous granules; the largest, occupying the middle of the convexity, 

 are about half a line in diameter, and gradually diminish in size to 

 the anterior border, and to within two inches and a half of the frac- 

 tured posterior end. The substance of the plate which sustains these 

 granules is calcified, but the calcareous layer is very thin, about one- 

 third of a line, and it coats a black internal horny layer, which extends 

 to the lateral margins, where the calcified outer layer gradually 

 changes into a horny one. This albuminous or horny part of the 

 body is much more extensive than in the Cuttle-bone, and differs 

 more materially by being continued through the centre of the sepium. 

 A little behind the rounded anterior border of the sepium, where the 

 finely granular calcified layer is broadest, the horny marginal plate 

 becomes half an inch in breadth, gradually increasing for nearly two- 

 thirds the extent of the shell to a breadth of one inch and a half, 

 when the margin suddenly expands and sweeps, with a convex curve, 

 backwards to the hinder end of the shell. These posterior expansions 

 have doubtless penetrated corresponding expansions of the mantle, 

 forming the hinder fins of the Cephalopod ; a part of the exposed 

 shale, which was in contact with the under or ventral surface of one 

 of these expansions, shows transverse fibrous markings indicative of 

 former muscular attachments of the part in question. The anterior 

 border of the shell is broad and rounded ; the posterior end appears 

 to have terminated more acutely, but this characteristic part of the 

 shell is unfortunately wanting. 



There is an indication at a fractured part near the middle line of 



