PLATE 41. 
h 247. 2. Cyrtolites trentonensis. (Pag. 189.) 
1 a. Lower surface of an imperfect specimen. 1 b. A portion of the surface striae enlarged. 
1 c. Section of the shell below the aperture ; the upper surface of the figure being the dorsal margin. 
250. 1. 
Lateral view of the fragment. 
Cyrtoceras lamellosum. 
2 b. Dorsal view of the same. 
(Pag. 193.) 
2 c. Magnified portion of the surface. 
248. 3. 
Cyrtolites filostjm. 
(Pag. 190.) 
3 a. Lateral view of the specimen imbedded in stone, the apex being concealed. 
3 b. View of the dorsal side of a small portion of the shell, showing the arched stria;. 
4, 5. 251. 2. Cyrtoceras annulatum. 
4 a. A large fragment (a cast), retaining the annulations. 
4 b. A smaller fragment, retaining the shell and transverse striae 
4 c. Section of the last, showing the siphuncle. 
4 d. A portion of the surface magnified. 
5. A fragment of the same species, nearer the aperture. 
6, 7. 257. 1 . Oncoceras constrictum. (Pag. 197.) 
6 a. View of the ventral side of an imperfect specimen. 
0 b. Lateral view of the same, showing the sudden contraction below the outer chamber : aperture imperfect. 
6 c. Section of the lower extremity, showing the small dorsal siphuncle. 
6 d. A smaller specimen, of the same form as the last. 
6 e. A shorter and more ventricose specimen. (The transverse lines on the upper half of the figure, indicating 
septa, are incorrect.) 
6/. The apicial extremity of the fossil. 
7 a, c. Dorsal and lateral views of a fragment, showing the direction of the septa. 
7 b, d. Sections of different specimens, showing the position of the siphuncle, and the narrowing of the dorsal 
side of the shell. 
(Pag. 194.) 
