PLATE LXX. 



Page. 



Fig. 1. Spirifer sp 552 



a. View of an unidentified dorsal valve. 



Madison limestone, east slope of Survey Peak, Teton Range. 

 Fig. 2. Spirifer striatns var. madisonensis n. var 551 



a. Dorsal view of a large specimen. 



b. Side view of same. 



Madison limestone, Crowfoot Ridge, Gallatin Range, top of bed 24. 



c. Dorsal view of a somewhat smaller specimen. 



d. Side view of same. 



Madison limestone, Crowfoot Ridge, Gallatin Range, cherty limestone, top of 

 bed 24. 

 Fig. 3. Spirifer centrotialns 547 



a. Ventral valve of a characteristic form ; after White. 



Waverly age, Mountain Spring, Old Mormon road, Nevada. 



b. A characteristic dorsal valve; after Hall and Whitfield. 



Waverly age, Dry Canyon, Utah. 



c. Another type, probably no more than varietally distinct from Spirifer centronatut, 



described by Hall and Whitfield as Spirifer albapineiisis; after Hall and Whitfield. 

 Waverly age, Logan Canyon, Utah. 



d. A young specimen of the general type of Spirifer albapinensis, referable to Spiri- 



fer centronatus; after Hall and Whitfield. 

 Waverly age, Dry Canyon, Utah. 



Fig. 4. Spirifer centronatus var. semifurcatiis u. var 549 



a. A dorsal valve of this type in which the incipient bifurcation of the two plications 

 surmounting the fold is less apparent than usual. 

 Madison limestone, Crowfoot Ridge, Gallatin Range, top of bed 26. 

 Fig. 5. Martinia rostrata n. sp 553 



a. Ventral view of a rather young specimen. 



b. Outline of the same, viewed from one side. 



Madison limestone, east side of Gallatin Rive"-, west of Electric Peak. 



c. Ventral view of an old specimen. 



d. Lateral outline of same, showing the elevated and produced beak. 



Madison limestone. 



e. A large dorsal valve, referred to this species. 

 /. Front view of same in outline. 



Madison limestone, Crowfoot Ridge, Gallatin Range, top of bed 25. 

 g. A very young ventral valve, described by Hall and Whitfield as Athyris planosul- 

 cata (f). After Hall and Whitfield. 

 Waverly age, Logan Canyon, Utah. 

 Fig. 6. Beticularia cooperensis var - o56 



a. Au exfoliated but otherwise perfect ventral valve. The heavy concentric lines are 



due to growth. Between these lie finer striae, the bases of the characteristic 

 spinulose fimbriations. 



b. Lateral outline of same. 



c. Posterior view of same. 



Eureka district, Nevada, Lower Carboniferous. 

 594 



