EXPLANATION OF PLATE LV. 



MYTILUS SMOCKI n. sp., ............................................. p. 502 



1-2. Two views of a complete internal cast which retains some 

 fragments of the shell. 



Navesink marl; near ll'alnford, (149}. 

 3-4. Two views of another complete internal cast. 



Navesink marl; near Crazvfords Corner, (126'). 



MYTILUS OBUVIUS Whitfield, ........................................ p. 503 



5. The type specimen illustrated by Whitfield. 



Wenonah sand; near Marlboro. 



6. View of the internal cast of a left valve. 



Wenonah sand; near Marlboro, (/jo). 



7-8. Views of the internal casts of two left valves doubtfully 

 referred to this species. 



Cliff-wood clay; Cliffivood Point, (105). 



MODIOLA MONMOUTHENSIS n. Sp., .................................... P- 5O4 



9-10. Views of two left valves. Internal casts. 



Merchantvillc clay-marl; near Mataivan, 



MODIOLA WENONAH n. sp ............................................. p. 507 



ii. View of the type specimen. 



Wenonah sand; near Marlboro, (130). 



MODIOLA JULIA Lea, ................................................ p. 506 



12-13. Views of two specimens, a right valve and a left valve. 

 Woodbury clay; Lorillard, 



MODIOLA JOHNSONI Whitfield, ....................................... p. 509 



14-15. Two views, lateral and cardinal, of the type specimen. 

 (After Whitfield.) 



Manasquan marl; Farmingdale. 



MODIOLA OVATA Gabb, ............................................... p. 508 



16. Lateral view of a specimen imperfect posteriorly. (After 



Whitfield.) 



17. View of the right side of the type specimen. (After 



Whitfield.) 



Vincentown formation; Timber Creek. 



MODIOLA BURLINGTONENSIS Whitfield, ................................ p. 505 



18-19. Cardinal and lateral views of the type specimen. (After 

 Whitfield.) 



Merchantvillc clay-marl; Burlington. 



MODIOLA SUBINFLATA Whitfield, ..................................... p. 507 



20-21. Cardinal and lateral views of the type specimen, (x2). 

 (After Whitfield.) 



Hornerstown marl; near Mullica Hill. 



992 



