CEPHALOPODA. 23 



Genus 1st. Belosepia.* Voltz. 1 830. 



Sepia. Cuvier; FSruaaaej dTOrbigmj ; Deshayes. 

 Belosepia. Bronn. 



Animal unknown ; but, from the affinities between its calcareous remains and the 

 internal shell of the recent Sepia, supposed to have more nearly resembled that genus 

 than any other existing Cephalopod, and may be thus described : 



Body oblong, (?) naked, supporting two lateral fins extending its whole length ; 

 mouth terminal, furnished with two corneous mandibles, and surrounded by ten 

 prehensile acetabulifcrous arms, of which two were longer than the others ; mantle 

 free at the anterior margin ; branchia two. 



Shell internal, oblong, semiconical, coarsely granulated or sulcated on the exterior, 

 internally smooth, containing a series of transverse laminae, perforated near their ventral 

 margins by large elliptical, sub-siphoniform openings, and terminating in a solid beak 

 or rostrum, inflected towards the dorsal aspect, and expanded at the anterior extremity 

 on the dorsal aspect into an elevated callus, and on the ventral aspect into a semi- 

 circular plate bent outwards over the base of the rostrum ; the ventral margins 

 of the lamina? converging towards the anterior extremity of the rostrum, and connected 

 by a thin calcareous plate. 



Testa interna, oblongd, semiconicd, externe granulatd, interne laevigata ; septa trans- 

 versa, foraminibus ventralibus ellipticis subsiphonoidis perforata, continenti, et rostro solido, 

 antice, parte dorsali in callum proemine?item, parte ventrali in laminam supra rostrum 

 rejlexam dilatato, postice sursum inflexo, terminatd ; septorum marginibus ventralibus ad 

 basbn rostri convergentibus et tenui lamina connexis. 



The remains of this extinct Cephalopod have been long known as of frequent 

 occurrence in the Paris basin ; they were noticed by Guettardf and were described by 

 him as the fossil teeth of sharks. They were also figured by Burtin,j and by him 

 were considered to be internal bones of a fish's head. To Cuvier palaeontology is 

 indebted for pointing out their true character. In a short notice published in 1824, in 

 the ' Annales des Sciences Naturelles,' that illustrious naturalist referred the remains 

 in question to a cephalopodous mollusc closely allied to the recent Sepia ; and, in fact, 

 they, as well as the remains of another extinct Cephalopod which exhibited an 

 unquestionably camerated and siphoniferous structure, and for the reception of which 

 the genus Beloptera had been established by M. Deshayes, were placed by M. d'Orbigny 

 in that genus. M. de Blainville also in the first instance described them as the remains 

 of a Sepia ; but afterwards, when he adopted the genus Beloptera for the Sepia 



* Etym. BeAos, telum ; Irjnia, sepia. 



•f Memoires sur differentes parties des Sciences et Arts, 1/83, Septieme Memoire, pi. 2, figs. 29-30. 



% Oryctyographie de Bruxelles (1784), pi. 2, fig. A. 



