PLATE 49. 



Fig. 1. Endoceras proteifoeme. (Pag. 213.) 



1 a. Ventral side of a fragment, showing the siphuncle, which is worn through in the lower part, exhibiting 

 the smooth embryo tube. This specimen shows the more abrupt arching of the septa as they approach 

 the siphuncle. 



I 6. A fragment, preserving the embryo tube. 



1 c. Transverse section of the last, which is slightly elliptical from compression. The embryo tube is pressed 

 against the upper side of the siphuncle, the outline of which is only faintly represented. 



1 d. A similar fiagment, embracing a portion of the embryo tube. In this one the septa are a little more ap- 

 proximate than in the other specimens, but it does not differ in other respects. 



1 f. A nearly perfect embryo tube, with a few of the septa of the parent shell still attached. 



In all these specimens, the septa are distant one-fo\irth to one-sixth the diameter of the outer shell. 



