PLATE 87. 
1. 376. 1 . Theca? triangularis. (Pag. 313.) 
I a. A portion of a large specimen, with the smaller extremity broken off. I c. Section of the same. 
1 b. A smaller specimen, very perfectly terminated at both extremities. 
1 d. A minute specimen of the same species. 
2. 375. 2. Ormoceras crebriseptum. (Pag. 313.) 
2 a. A part of the outer chamber of this species. 
2 b. A fragment still preserving a portion of the shell, showing some strong longitudinal strise, 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. 
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