PLATE XXI. 



Cyphosoma texanitm Roemer (p. 60). 



U. S. Nat. Mus. 9838. 



Figure la. Upper surface of the test, 

 lb. Lower surface of the test, 

 lc. Lateral surface of the test. 

 Id. Tubercle, X 10. 

 le. Ambulacrum, X 3. 

 If. Portion of interambulacrum, X 3. 

 lg. Portion of ambulacrum, X 8. 



Cyphosoma volanum Cragin (p. 61). 



Geol. Survey Texas, type, specimen A. 



Figure 2a. Upper surface of the test, X 2. 

 2b. Lower surface of the test, X 2. 



Cyphosoma volanum Cragin (p. 61). 



Geol. Survey Texas, type, specimen B. 

 Figure 3. Upper surface of the test. 

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