PLATE C. 



PAGE 



Pig. 1. Pectex (Chlamys) madisonius Say 377 



1. Exterior of left valve. Flag Pond. x 14 



Fig. 2. Pecten (Chlamys) jeffersoxius Say 378 



2. Exterior of right valve. St. Mary's River. x % 



Pig. 3. Pecten jefferronius var. edgecombensis Dall 379 



3. Exterior of left valve. St. Mary's River. U. S. National 



Museum. X l^ 



Pig. 4. Pecten jeffeesonius var. septenabius Say 379 



4. Exterior of right valve. Petersburg, Virginia. U. S. National 



Museum. x i^ 



Pigs. 5a, 5b. Ostrea sell^formis var. thomasii (Conrad) 380 



5a. Exterior of type specimen. Charles county near the Patuxent 



river. Acad. Nat. Sci., Phila. 

 5b. Interior of the same specimen. 



