MOLLUSCA. 665 



Formation and locality, — Navesink marl, near Arneytown 

 (Morton). 



Geographic distribution. — New Jersey. 



Sub-order RHIPIDOGLOSSA. 



Family PLEUROTOMARIIDAE. 



Genus PivSUROTOMARiA Defrance. 



Pleurotomaria crotaloides (Morton). 



Plate LXXV., Figs. 7-9. 



1834. Cirrus crotaloides Mort., Synop. Org. Rem. Cret. Gr. U. 



S., p. 49, pi. 19, fig. 5. 

 1861. Plewrotomaria crotaloides Gabb, Synop. Moll. Cret. 



Form., p. 125 (69). 

 1861. Architectonica Ahhottii Gabb, Proc. Acad. Nat. Sci. Phil. 



(1861), p. 321. (In part.) 

 1864. Pleurotontaria ( ?) crotaloides Meek, Check List Inv. 



Fo'ss. N. A., Cret. and Jur., p. 18. 

 1864. Margaritella Abbotti Meek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 18. 

 1868. Margaritella Abbottii Con., Cook's Geol. N. J., p. 728. 

 1892. Margaritella Abbotti Whitf., Pal N. J., vol. 2 (Monog. 



U. S. G. S., vol. 18), p. 134, pi. 17, figs. 12-15. 

 1896. Pleurotomaria crotaloides Pils., Proc. Acad. Nat. Sci. 



Phil. (1896), p. 10, pi. I, figs. 1-3. 

 1905. Pleurotomaria crotaloides Johns., Proc. Acad. Nat. Sci. 



Phil. (1905), p. 19. 

 1905. Margaritella abbotti Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), P- 20. 



Description. — ^"Shell of medium size, subdiscoid with a very 

 low, depressed-convex spire and nearly flat base; volutions four 

 or five, rather slender, coiled one below the other, their upper sur- 

 faces rounded, with deep suture line, keeled on the periphery in 

 the cast, and very depressed convex on the lower side between the 



