EXPLANATION OF PLATE XXX. 



PEreisonota proTexta Conrad, p. 379 



1-2. Views of two internal casts of left valves, showing the 

 impression of the hinge. 



Red Bank mud ; Shrcwsbiii-y River, (ng). 



Y0I,DIA CLIl'I'WOOtlEXSIS 11. Sp p. 3S3 



3. The internal cast of a left \-al\'e, imperfect posteriorly. 



Cliffw.uid clay; Cliff i^-ood Point. {1S5). 



4. The internal cast of a right \alve. 



Cliffzvood clay; near J/u/uteu)/, liO/). 



YoLDiA LONGii-KONS ( Conrad ) p. 381 



5. A very perfect internal cast of a left valve, showing the 



impression of the hinge. 



Woodbury clay; Lorillard, (102). 



YotDiA PAPYRiA ( Conrad ) p. 382 



6. View of an internal cast of a right valve, showing the 



impression of the hinge. 



Woodbury clay; near Malaiean, (JOJ). 



Nemodon conradi Johnson p. 387 



7. The internal cast of a right valve. 



IJ'oodbui'y clay; Lorillard. (1112). 



Nemodon euFaui.ensis ( Gal.)b ) p. 385 



8. The internal cast of a right valve. 



Merchantvillc clay-marl; near Janicsburg, (i39). 

 g. The internal cast of a left valve. 



Red Bank sand; Red Bank. (116). 



10. The internal cast of a left valve. The specimen illustrated 



by Whitfield. 



yavcsink marl. 



11. A small form doubtfully referred to this species. 



I'ineeutoien loi-ination ; near I'armingdale, (134). 



Nemodon brevifrons Conrad p. 389 



12. A very perfect internal east of the riglit valve. 



Cliffioood clay; Cliffwood Point. (los). 



13. The internal cast of a right vah'c. 



fj'enonah sand; near Marlboro, (130). 



14. The internal cast of a large left valve referred doubtfully 



to this species. 



iVenonah sand; near Craivfoi'ds Corner, (126'), 



Nemodon ANCtT,.\TUM (' Gabb ) p. 38S 



15. The left side of the type specimen. (After Whitfield.) 



A^avesink marl? 



941. 



