8 DESCRIPTION OF 



PLATE VII, 



Page 



Fig. 1. CHONETES PISCHERI. 517 



1 a. A specimen in sandstone, which preserves no radiating striae. 



1 b. A specimen in limestone, which partially preserves the radiating striae. 



1 c. Enlargement of the surface, showing the radiating striae and diagonal 

 lines. 



Fig. 2. PRODUCTUS SHUMARDIANUS. 499 



2. View of the ventral valve. 



Fig. 3. PRODUCTUS CONCENTRICUS. 517 



3. View of the interior of the dorsal valve of this species. 



Fig. 4. . PRODUCTUS ARCUATUS. 518 



4 a. View of the ventral valve. 



4 b. Profile view of the same. 



. 

 Fig. 5. SPIRIPER BIPLICATUS. 519 



5 a. Dorsal valve from the Oolitic beds below the Burlington limestone. 

 5 b. Cast of a dorsal valve from the Yellow sandstone. 



Fig. 6. SPIRIPER EXTENUATUS. 520 



6. Dorsal valve of this species. 



- 



Fig. 7. SPIRIFER CAPAX. 520 



7 a. Dorsal valve of a large individual. 

 7 6. Ventral valve of the same. 

 7 c. Profile view. 



7 d. Cardinal view, showing height of area and foramen. 



Fig. 8. SPIRIPER SUBROTUNDATUS. 521 



8 a. Cast of the dorsal valve of this species. 



8 b. Cast of the ventral valve, showing the narrow elongate muscular im- 

 pressions below the beak 



Fig. 9. AVICULA CIRCULT7S. 522 



9. The right valve of this species. 



Fig. 10. CARDIOMORPHA OVATA. 522 



10 a. The right valve of a specimen, which shows an obtuse ridge from 

 the beak towards the base. 



10 b. A similar valve, where the surface is more uniformly convex, and 

 without a ridge. 



10 c. Profile of the same specimen. 



