PLATE 45. 
Fig. 1. 274. 6. Endoceras proteiforme, var . tenuistriatum. (Pag. 209.) 
1 a. Fragment of the young shell, natural size, showing only the transverse striae. 
1 b. Enlarged portion, showing the longitudinal striae. 
Fig. 2, 3, 5. 275. 7. Endoceras proteiforme, var . tenuitextum. (Pag. 210.) 
2 a. A fragment of a tube destitute of septa, presenting strong transverse and longitudinal striae. 
2 b. A portion of the surface enlarged. 
3 a. A specimen with finer striae, showing the marks of septa. 3 b. Portion of the surface enlarged. 
5 a. This specimen presents a double tube or sheath, the outer one (or embryo tube) being entirely smooth ; 
while the inner one, which is but little smaller, is marked by longitudinal and transverse stria; as in the 
preceding figures. 
5 b. A portion of the same enlarged to show the striae. 
5 c. A section of the same, showing no septa or siphuncle. 
Fig. 4. 276. 8. Endoceras proteiforme, var . lineolatum. (Pag. 211.) 
4 a. A young shell, with the outer chamber and apex broken off. 
4 b. Transverse section of the larger extremity, showing the position of the siphuncle. 
4 c. A fragment of the smaller extremity of the shell, which is annulated by fine sharp ridges. 
4 d. The same enlarged. 
4 e. A fragment of another tube, marked like 4 a, showing at the lower extremity a septum and siphuncle. 
