118 



NEW YORK STATE MUSEUM 



Shell snbtriangular in outline with the valves nearly equally 

 and moderately convex. Pedicle valve vs^ith the beak over- 

 arching that of the brachial valve, more s'trongly arched in the 

 posterior than in the anterior portion. Greatest width about 

 two thirds the distance from the beak to the anterior margin. 



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^i 



"^d 



e . ' h 



Fig. 27 Camarotoechia semiplicata var. ang-ulata var. nov. (much enlarged) 



Anterior third to half only, marked by broad rounded plications, 

 which become angular toward the front in the adult. These 

 plicae arise gradually from the nonplicate surface. Two plica- 

 tions near the center border a narrow median depression in 

 which there is a median faint, rounded plication. Two to three 

 fainter jDlications occur outside those bounding the sinus, on 

 each side. 



