496 CRETACEOUS PALEONTOLOGY. 



this with any certainty, and the specimens preserving the shells 

 will be considered as the types of the species. These specimens 

 are two- in number from Marshalltown, N. J., and they undoubt- 

 edly came from the Marshalltown clay-marl. Several additional 

 specimens of the same form are preserved in the more recent 

 collections of the Survey from the same formation near Swedes- 

 boro, and these, with some others from the Navesink marl, pre- 

 sent additional features of the shell not seen by Whitfield, which 

 show the species to be a member of the genus Plagiostoina. 

 Whitfield's figure of the specimen preserving the shell (fig. 17), 

 either was considerably restored in the drawing, or the specimen 

 has been injured since he studied it. This specimen does not 

 .retain the posterior auriculation oi the shell, although after 

 observing it in other individuals, it may be seen that it was 

 originally present in this type. The species may be compared 

 with P. hoperi Mant., from the upper chalk of England.^ 



Formation and locality. — Marshalltown clay-marl, Marshall- 

 town (Whitfield), near Swedesboro (177, 179, 180); Navesink 

 marl, near Crawfords Corners (126''), near Holmdel (128^), 

 Cross wicks Creek (149). 



Geographic distribution.— i^e^'^ Jersey. 



Super-family ANOMIACEA. 

 FamUy ANOMIIDAE. 



Genus Anomia Linneus. 



Anomia argentaria Morton. 



Plate UV., Figs. 11-15. 



1833. Anomia argentaria Mort., Am. Jour. Sci., ist ser., vol. 

 23. P- 293, pi. 5, fig. 10. 



1833. Anomia tellinoides Mort., Am. Jour. Sci., ist ser., vol. 



23, P- 294, pi. 5, %• II- 



1834. Anomia argentaria Mort., Synop. Org. Rem. Cret. Gr. 



U. S., p. 61, pi. 5, %. 10. 



^ Woods, Monog. Cret. Lam. Eng., vol. 2, pt, i, p. 17, pi. 4, figs. 7-12. 



