PLATE I. 



Fig 1. Corhuhi Krebsiana C. B. Adams; 6.1. Page 316. 

 1 a. 



1 b. 



2. Basterotia qnadmta Y{\nAs ; 10 ; left valve. Page 316. 



2 a. Same, hinge seen from above. 



2 b. " " " below. 



3. Corhula Knoxiana C. B. Adams ; 12.7; front. Page 313. 



3 a. " " back of left valve. 

 3 b. 



3 c. 



4. Corbula disparilis D'Orbigny ; 9.0. Page 314. 



4 a. 



4 b. 



5. Corbula Dietziana C. B. Adams ; 10.7. Page 314. 

 6 a. 



5 b. 



6. Corbvla Kjoeriana C. B. Adams ; 12. Page 316. 



6 a. 



6 b. " 



7. Corbula a/mella Dall ; 13.5. Page 315. 



7 a. 



All the above, except figures 2 a, 2 b, and 4, 4 a, 4 b, are drawn from typical 

 specimens of the describer. 



