PLATE 32 



Spirifer murchisoni Castelnau 



Page 177 



I, 2, 4 Ventral valves 

 3, 5 Dorsal valves 



Grande Greve limestone. Perce Rock 



6 Internal cast of dorsal valve 



7 Silica replacement of ventral valve, inside view 



8, 9, 10 Silica replacements of ventral valves retaining the surface 

 characters 

 Grande Greve limestone ; divisions i and 2. Grande Greve 



Spirifer fimbriatus (Conrad) 



Page j8o 



1 1-13 Three views of an excellent specimen, rare in this fauna, introduced 

 for comparison with the following species. This species has 

 duplicate spines on the fimbriae. 

 Oriskany siliceons limestone. Glenerie, N. Y. 



Spirifer cyclopterus (Hall) Billings 



Page 178 



14 Cardinal view of one of Billings's originals 



15 Enlargement of the surface, x 10 

 Grande Greve limestone. Perce Rock 



16, 17 Opposite sides of another of Billings's original specimens 



18 Internal cast of a ventral valve 



19, 20 Exterior of ventral and dorsal valves 



21 Enlargement of surface, x 5 



Grande Greve limestone. Grande Greve 



While figure 14 represents a very characteristic example of S . cyclop- 

 terus Hall, differing from S. fimbriatus in its more sharply defined 

 ribs and simple fimbriae, figures 16-21 are of a type which allows ready 

 inclusion within the conception of S . cyclopterus, but is not to be 

 easily distinguished from either that of S. tribulis or of S. saffordi 



Hall, both species of the Cumberland Oriskany. 



316 



