PLATE XI. 



Spirifera mcconathii. 



Fig. 1-6. Ventral, cardinal, dorsal, front and Drotile view of a speci- 

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Spirifera divaricata. 



Fig. 6-10. Dorsal, front, cardinal, ventral and profile view of a speci- 

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 Fig. 11. An enlargement of a portion of the test of a specimen. 



