PLATE XVII. 



Orthopsis occidentalis Cragin (p. 54). 



Geol. Survey Texas, type. 



Figure la. Upper surface of the test. 

 lb. Lower surface of the test, 

 lc. Lateral surface of the test. 

 Id. Ambulacrum, X 3. 

 le. Portion of ambulacrum, X fi- 

 ll Portion of interambulacrum, X 3. 

 lg. Portion of apical system, X 4. 

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