PLATE 87. 



Fig. I. 376. 1. Theca? TRiANGULAEis. (Pag. 313.) 



I a. A portion of a large specimen, with tlie smaller extremity broken off. 1 e. Section of the same. 



1 4. A smaller specimen, very perfectly terminated at both extremities. 



1 </. A minute specimen of the same species. 



Fig. 2. 375. 2. Ormoceras crebriseptum. (Pag. 313.) 



2 o A part of the outer chamber of this species. 



2 6. A fragment still preserving a portion of the shell, showing some strong longitudinal striie, and the dorsal 



line or ridge. 

 2 c. A fragment showing the position of the siphuncle on the highly arched septum at the upper extremity of 



the figure. 

 2 d. A fragment of stone, with numerous small specimens of this species, associated with crinoidal joints. 

 2 e. A longitudinal section of a fragment, showing the deeply arched septa, and the alternate enlargement and 



contraction of the siphuncle. 

 ,*, These figures are all erroneously marked 4 on the plate. 



