PLATE XXX 



PAGE 



Figs. 1, 2. CONOCARDIUM NORMALE Hall 257 



Right side and cardinal view of large partial cast of exterior. Romney 

 formation, Hamilton member, Cumberland. (After Hall.) 



Figs. 3, 4. COXOCARDIUM CUMBERLANDI.E Swartz n. sp 257 



Right side and ventral view of type. Romney formation, Hamilton 

 member, Williams Road, 3% miles east of Cumberland. 



Figs. 5-8. ACTINOPTER.IA DECUSSATA Hall 258 



5. Partly exfoliated left valve. 



6. Left valve. 



7. External impression of a portion of a left valve, showing the char- 



acter of the surface markings. 



Romney formation, Hamilton member, road east of Pine Hill, 

 about 4 miles north of Oldtown. 



8. A large right valve. Hamilton formation, New York. 



Figs. 9, 10. ACTINOPTERIA BOYDI VAR. GiBBosA Prosser n. var 259 



9. Right valve. 

 10. Left valve of same specimen. 



Romney formation, Hamilton member, Town Creek, 4 miles 

 northeast of Oldtown. 



Fig. 11. ACTINOPTERIA sp 260 



Left valve, surface markings mostly obliterated over the umbonal 

 region. Romney formation, Hamilton member, Iron Bridge over 

 Town Creek, northeast of Oldtown. 



113 



