PLATE XVII. 



Page. 

 Mytilus oblivius Whitfield 64 



Fig. 1. View of the only specimen known, natural size. 



LiTHODOMUS AFFINIS Gabb 6Q 



Fig. 2. Lateral view of Mr. Gabb's type specimen, natural size. 



3. Cardinal view of the same. 



LiTHODOMUS RiPLEYANA Gabb 67 



Fig. 4. Lateral view of a very entire cast of a shell, showing the callus at the posterior end; 

 one of the originals. 

 5. View of a group of the barrows which have been made in wood, from MuUica 

 Hill, N. J. 



MoDiOLA Julia Lea , 64 



Fig. 6. Lateral view of Mr. Lea^s type, twice enlarged. 



7. View of a specimen from another locality, natural size, doubtfully referred to this 

 species. Comp, M. Johnsoni, 



MODIOLA BURLINGTONENSIS Whitfield , 65 



Fig. 8. Lateral view of the type specimen, from Burlington, N. J. 

 9. Cardinal view of the same. 



Crassatella (Etea) prora Conrad 120 



Fig 10. Lateral view of the type. 

 11. Cardinal view of the same. 



Crassatella vadosa Morton 116 



Fig. 12. Right view of an internal cast. 



13. Cardinal view of the same. 



14. View of a specimen preserving some of the shell substance, showing the concentric 



markings. From Freehold, N. J. 

 15. Similar view of another specimen from the same locality. 



Crassatella transversa Gabb 122 



Fig. 16. Lateral view of the type specimen. 

 17. Cardinal view of the same. 



Crassatella cuneata Gabb 118 



Fig. 18. View of a specimen, natural size. 



19 and 20. Views of a cast of this species, enlarged to two diameters. 



Crassatella Monmouthensis Gabb 119 



Fig. 21. View of the right side of a cast of this species, Mr. Gabb^s type. 

 22. Similar view of another cast. 



302 



