PLATE CV. 
Fig. 1. Arca (Scapharca) clisia Dall 
1. Interior of left valve. Nomini Cliffs, Virginia. 
Museum. 56 mm. (After Dall.) 
PAOE 
386 
U. S. National 
Figs. 2-6. Arca (Scapharca) staminea Say 
2. Interior of left valve. Flag Pond. 
3. Interior of left valve of short variety. Same locality. 
4. Exterior of right valve. Same locality. 
5. Exterior of right valve. Dover Bridge. 
6. Interior of left valve. Peach Blossom Creek. 
387 
Figs. 7a, 7b. Arca (Scapharca) arata Say 
7a. Interior of right valve. St. Mary's River. 
7b. Exterior of left valve. Same locality. 
388 
97 
