PLATE IV. 



PAGE. 



Fig. 1. Endoceras EGANI, u. sp., natural size. — The internal tube arises in 

 the siphuncle at the dotted line indicating the enlargement of a 

 chamber, the fracture shows where it is broken off, and from there 

 to the end of the specimen it continued to enlarge; figs, la and lb 

 represent a specimen broken in two parts, and one of them turned 

 over. These specimens show the pointed cuneiform character of 

 the internal tube, 84 



Figs. 2a and 2b. Exdoceras bristolexse, n. sp. — This species has a very rapid 

 conical enlargement of the internal tube until it fills nearly the 

 entire siphuncle, 85 



Figs. 3 and 3a. Endoceras in^quabile, n. sp., natural size of siphuncle, . 86 



Fig. 4. Cancellaeia liyingstonexsis, n. sp.— View of the dorsal side that 

 would be improved if drawn on a line parallel with the plate, or 

 with 4« ; fig. 4a, an imperfect view of the aperture, ... 86 



