PLATE 47. 
1, 2. 274. 6. Endoceras proteiforme, var . tenuistrIatum. (Pag- 209.) 
1 a. A small and slender specimen of this species. 
1 b. A portion of the surface enlarged, showing the cancellated lines. 
2 a. This specimen presents very similar surface markings, and cannot be distinguished from the last, though 
the transverse stri® are less prominent. The specimen consists of a double or triple tube; the outer one 
2 b showing externally marks of septa, which are distant about one-fourth the diameter. The shell is 
exfoliated, and the surface markings are unknown. 
2 c. An enlarged portion of the surface : the longitudinal stri® are too strong in the figure. 
2 d. A small portion still farther magnified, showing the proportionate size of the transverse and longitudinal 
striae. 
2 e. Transverse section of the specimen 2 a, showing the proportional diameters of the two, and the section 
of a still smaller tube within 2 a. 
3. 269. 22. Orthoceras junceum. (Pag- 204.) 
3 a. A fragment denuded of the shell, showing a part of the outer chamber, and septate portion of the tube. 
3 b. A smaller specimen, showing the marks of septa which appear to be slightly oblique. 
3 c. A small fragment, showing the convexity of a single septum. 
3 d. A section of the last, showing the central position of the siphuncle. 
3 e. A small fragment, showing the closer approximation of the septa near the outer chamber. 
3 f A small fragment, preserving the shell and the striated surface. 
4. 276. 8. Endoceras proteiforme, var . lineolatum. (Pag. 211.) 
4 a. A fragment from the apex of one of these tubes, which is septate as in the larger specimens. 
4 b. A transverse section. 
4 c. A fragment which is annulated near the apex, and septate to the extreme point. 
4 d. Section near the apex. 
4 e. A fragment of a similar young shell, where the lamellose stris have become vesicular, giving a rough 
scaly appearance to the surface. 
