398 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 42. 



Cliopteria unicosta Williams. 



Fig. 3. A left valve showing the beak and umbonal ridge with a shallow furrow and 

 single ridge on the anterior slope. 

 4. A right valve, the single ridge separated by slight furrow from the umbonal 



ridge. 

 6. A right valve, same specimen as fig. 4, cardinal view showing the overarching 

 beak and flat high area; locality same as for figs. 1, 2, and 7. 



Pterinea laxata Williams. 



Figs. 5 and 5a. Molds of the interior of a left and a right valve, introduced here for 



comparison with corresponding valves of Cliopteria (figs. 7 and 2). 



Shales at the head of Leighton Cove, Pembroke, Maine. Collected 



by C. L. Breger. 



Streptotrochus carinatus Williams. 



Fig. 8. An exfoliated specimen showing the interior surfaces of the whorls with 

 angular carinse near the outer sulcus. Magnified 2 diameters. Shales in 

 the cove on west side of Shackford Point on Moose Island, Eastport, Wash- 

 ington County, Maine. 



Streptotrochus sulcatus Williams. 



Fig. 9. A partially exfoliated specimen, magnified 2 diameters, showing the revolv- 

 ing furrow and the concentric surface lines; collected by H. S. Williams. 

 Locality same as fig. 5. 



Eurymyella convexa Williams. 



Fig. 10. Mold of the interior of a left valve, natural size, showing the anterior mus- 

 cular scar, umbonal and pedal scars, and, obscurely, a cardinal tooth under 

 beak and a short oblique posterior tooth near hinge extremity. Salt 

 Works, Eastport. Collected by N. S. Shaler. 



Eurymyella denbowensis Williams. 



Fig. 11. A mold of the interior of front part of a right valve, natural size, showing the 

 anterior muscular scar, umbonal and pedal scars, and the small oblique 

 cardinal tooth under the beak. Southeast comer of Denbow Point, forming 

 the northern extremity of Denbow Neck, Lubec Township, Washington 

 County. Collected by C. L. Breger. 

 14. A nearly complete left valve, partially exfoliated, showing the anterior and 

 pedal scars, the flattened cardinal area without lateral cardinal teeth, and 

 the surface markings. 

 Locality same as fig. 11. 



St'eptotro<Jius regularis Williams, 



Fig. 12. An uncrushed specimen, showing the outer surface of the shell and the eub- 



regular convexity of the body whorls. Magnified 2 diameters. Collected 



by H. S. Williams. 

 Locality same as fig. 8. 



Streptotrochus ione Williams. 



Fig. 13. A nearly perfect shell, showing the carination on the next to last whorl and 

 sulcus on outer whorl and surface markings. Magnified 2 diameters. Col- 

 lected by H. S. Williams. 

 Locality same as fig. 8. 



