PLATE LXVI. 



Patre. 

 Fig. 1. Atrypa reticularis 502 



a. Type usually found in Yellowstone National Park; after Walcott. 



b. Lateral view of same; after Walcott. 



Devonian, Eureka district, Nevada. 



c. View of another specimen; after Meek. 



(?) Middle Devonian, Piiion station, White Pine district, Nevada. 

 FlG. 2. Atrypa missouriensis 502 



a. Rostral view of a small individual, of a type common in Yellowstone National 



Park ; after Walcott. 



b. Ventral aspect of same ; after Walcott. 



Devonian, Lone Mountain, Nevada. 



c. Dorsal view of another specimen ; after Meek. 



Middle Devonian, Piiion station, White Pine district, Nevada. 

 Fig. 3. Sjririfer engelmanni 504 



a. An anterior view ; after Meek. 



b. Cardinal view, showing area and foramen; after Meek. 



c. Side view of same; after Meek. 



d. Dorsal view of same ; after Meek. 



Middle Devonian, Nevada. 

 Fig. 4. Afhyris vittata var. Iriplicala n. var 504 



a. Lateral view of type specimen. 



b. Dorsal view of same. 



c. Anterior view of same. 



Three Forks limestone, south side of Soda Butte Creek, northwest of Abiathar 

 Peak, Ahsaroka Range. 



Fig. 5. Pleurotomaria isaacsi ( f ) 505 



a. Specimen doubtfully identified with Hall and Whitfield's species. 

 '). Side view of same. 



Three Forks limestone, Wall Canyon, Clark Fork Valley. 



Fig. 6. Loxonema delicatum u. sp 506 



a. View of type specimen, enlarged. 



Three Forks limestone, south side of Soda Butte Creek, northeast of Abiathar 

 Peak, Ahsaroka Range. 

 Fig. 7. Platystoma minutum n. sp 506 



a. Apical view of type specimen, enlarged. 



b. Lateral aspect of same, enlarged. 



Three Forks limestone, south side of Soda Butte Creek, northeast of Abiathar 

 Peak, Ahsaroka Range. 



Fig. 8. Favosites sp 501 



a. Silicified example, showing size of corallites and character of tabulation. 

 Three Forks limestone, north side of Soda Butte Creek, Ahsaroka Range. 



FlG. 9. Loxonema (?) sp 572 



a. Lateral view of an internal cast. 



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

 580 



