CLASSIFICATION. 29 



Acanthoteutliis,^ Wagner. 



The shell is not known ; probably identical with Belemnosepia. The hooks were in 

 double rows along ten nearly equal arms. (Example — A. prisca. Oolite of 

 Solenhofen.) 



Belemnoteuthis, Pearce, 1842. 



Shell consisting of ^ phragmocoiie like that of the Eelemnite, a horny dorsal pen, 



with obscure lateral bands, and a thin fibrous guard, with two diverging ridges 



on the dorsal aspect. 

 Animal provided with arms and tentacula of nearly equal length, furnished with a 



double alternating series of horny hooks, from tvrenty to thirty pairs on each 



arm ; mantle free all round ; fins large, mediodorsal. (Example — B. aniiqua. 



Oxford Clay.) 



Conoteuthis, D'Orb. 



Phragmocone slightly curved. Pen elongated, very slender. (Example — C. 

 Bupiniana. Neocomian.) 



In 1863 Karl Mayer presented, in the 'Journal de Conchyliologie,' the fol- 

 lowing classification of Jurassic Belemnites, which is illustrated by the collection in the 

 Zurich Museum : 



AcuAKii. Lanceolate, laterally compressed, without canal or lateral grooves. Lias 

 and Oolite. 



A. Smooth. AA. Alveolus excentric. 

 AAA. Alveolus central. 



B. With furrows at the apex. 



BB. Alveolus central. 

 BBB. Alveolus excentric. 



Canaliculati. Lanceolate, with ventral depression, but no lateral grooves. Oolite. 



A. Smooth. A A. Alveolus excentric. 



AAA. Alveolus central. 



B. Unisulcate. BB. Alveolus central. 



BBB. Alveolus excentric. 



C. Bicanaliculate. 



^ Professor E. Suess has lately given figures and descriptions of the Acanthoteuthidae, ' Proceedings 

 of the Imperial Academy,' Vienna, 1865. 



5 



