24 PROCEEDINGS OF THE ISTATIOlSrAL MUSEUM vol.72 



Plate 4 

 Cassidiilus emmonsi Stephenson (p. 7) 



Fig, 1. Upper surface of the test of a typical specimen from a well at the water- 

 works at Wilmington, depth not stated. U. S. Nat. Mus. Oat. No. 

 28930. 



2. Lower surface of the test of the specimen shown in Figure 1. 



3. Part of the upper surface of the same specimen, X3. 



4. The peristomal area of the same specimen, X3. 



5. Diagrammatic representation of part of the left antero-lateral ambula- 



crum of a typical specimen, X4. U. S. Nat. Mus. Cat. No. 73424. 



Plate 5 

 Linthia variabilis Slocum (p. 10) 



Fig. 1. Upper surface of a specimen from Hilton Park, Wilmington, N. 0. 

 U. S. Nat. Mus. Cat. No. 73426; the test has been slightly flattened 

 by crushing from above. 



2. Lower surface of the specimen shown in Figure 1. 



3. Right lateral surface of the same specimen. 



4. Upper surface of a smaller specimen from Hilton Park which has been 



crushed laterally, and made to appear narrower than normal. U. S. 

 Nat. Mus. Cat. No. 73426. 



5. Lower surface of the specimen shown in Figure 4. 



6. Right lateral surface of the same specimen. 



7. The same enlarged, X2. 



Glycymeris suhgyrata Stephenson (p. 12) 



Figs. 8, 9. The type, a left valve. U. S. Nat. Mus. Cat. No. 73428. 

 8a. Profile showing the convexity of the type. 



Lima insoUta Stephenson (p. 13) 



Fig. 10. The type, a right valve. U. S. Nat. Mus. Cat. No. 73431. 



Anomia inajor Stephenson (p. 13) 



Fig. 11. The type, a left valve. U. S. Nat Mus. Cat. No. 73432. 



Anomia penderana Stephenson (p. 14) 



Fig. 12. The type, a left valve. U. S. Nat. Mus. Cat. No. 73434. 



Plate 6 



Pholadomya suMevis Stephenson (p. 15) 



Fig. 1. Left side of the type, an internal cast on which the external markings 

 of the shell have been impressed by pressure after the removal of the 

 shell by solution. U. S. Nat. Mus. Cat. No. 73435. 

 2. View of the upper surface of the type, showing also the convexity of 

 the shell. 



Veniella (Etea) grandis Stephenson (p. 16) 



Figs. 3, 4. The type, a right valve. U. S. Nat. Mus. Cat. No. 73436. 

 3a, Profile showing the convexity of the type. 



