PLATE 37. 
Figs. 1-4. SpiRIFBRA GRANIJLIFERA var. CLINTONI. 
1. Dorsal view of a small individual. 
2. Yentral view of the same. 
3. Profile of the same. 
4. Yentral view of a much larger specimen. 
Fig. 9. Spirifera medialis ?. 
9. Dorsal view of a young specimen, doubtfully referred to this species. 
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228 
Figs. 10-20. Spirifera marcyi .. 226 
10. Dorsal view of a small individual of this species. 
11. Yentral view of the same. 
12. Cardinal view of the same. 
13. Dorsal view of an unsymmetrical specimen of gibbous form, showing the area and foramen. 
14. Yiew of a ventral valve of another individual. 
15. Ventral view of a more extended form. The front of the shell is shortened by crushing. 
16. Profile view of specimen fig. 13, showing the great rotundity of the dorsal valve. 
17. Interior of a dorsal valve, showing the cardinal process and dental sockets. 
18. Enlargement of surface, showing the elongated pustulose markings characteristic of this 
species. 
19. Cardinal view of'an individual, which is imperfect at the extremities. The valves are less 
gibbous than in fig. 16. 
20. Interior of an imperfect ventral valve, showing the broad muscular impression. 
