﻿ii5 Paleontology 37 



PLATE II. 



Schuchertella chemungensis var. arctostriatus 26 



Fig. 1. View of ventral valve, Livingston, Mont, (x 1) 

 1 a. View showing detail of surface stria? (x 4) . 

 ib. Side profile outline of specimen shown in fig. 1 . 

 ic. A dorsal valve of small specimen, Princeton, Mont, (x 4) 



Spirifer utahensis 3 1 



F g. 2. View of ventral valve. Princeton, Mont, (x 1) 

 2a. View of the area of the same specimen. 

 2b. A dorsal valve. Princeton, Mont, (x 1) 

 2C. Dorsal valve of specimen showing more prominent fold 

 than fig. 2b. Princeton, Mont, (x 1) 



Spirifer engelmanni 3 2 



Fig. 3 . View of a ventral valve. Princeton, Mont, (x 2) 

 3a. Side profile view of the same specimen. 

 3b. View of a dorsal valve of another specimen. Princeton, 

 Mont., (x 1) 



Spirifer cf . argentarius 3 2 



Fig. 4. View of area and beaks of an exfoliated shell. Princeton, 

 Mont., (x 2) 

 4a. A ventral view of the same specimen, the termination of 

 the plications anterior to the umbonal region in this and 

 the preceding figure is due to exfoliation of the shell. 



