PELECYPODA—TELEODESMACEA. 



575 



Merchantville-Red Bank of New Jersey ; especially character- 

 istic of the Woodbury. Also in Mississippi, Arkansas, Texas. 



599. C. subcompressa Gabb. (Fig. 789.) 



Eocenic. 

 Umbonal ridge angular with slope abrupt. 

 Midway (basal Eocenic) of Alabama, Tennessee, 

 Arkansas. 



600. C. aldrichi Meyer. (Fig. 790, d, e.) 



Eocenic. 



Umbos without concentric lines but marked with radiating striae. 

 Maryland, Alabama. 



601. C. oniscus Conrad. (Fig. 790, a-c.) Eocenic. 

 Solid, with numerous and wrinkled concentric lines. 

 Maryland, Virginia and the Gulf region. 



Fig. 789. 

 Corbula subcom- 

 pressa. (After 

 Harris. ) 



Fig. 790. a-c, Corbula oniscus, right valve and cardinal view 

 right and left valves. (Md. Surv. ) 



C. aldrichi. 



CLXXIX. Saxicava Fleuriau. 

 Small, equivalve, oblong, elongated, gaping and hence not fully 

 covering the animal. Umbones anterior. Ligament external. 

 Teeth absent in adult ; consisting of one or two cardinals in the 

 young. No laterals present. Surface rugose. Pallial line sinu- 

 ated, discontinuous. Bores into soft rocks. Tertiary-Recent. 

 602. S. arctica (Linne). (C. rugosa.) (Fig. 791.) 



Miocenic-Recent. 



