826 CRETACEOUS PALEONTOLOGY. 



collection of the Walker Museum at the University of Chicago, 

 except that the transverse ribs which cross the ventral side only 

 of the New Jersey specimen, continue in the type without inter- 

 ruption to the umbilical margin. This same difference between 

 the New Jersey and the western specimens is noticeable in all 

 the examples from both regions which have come under obser- 

 vation in which the markings of the sides of the shell can be seen. 



Formation and locality. — ^Merchantville clay-marl ?, New Jer- 

 sey (Whitfield) ; Woodbury clay, Lorillard (102). 



Geographic distribution. — New Jersey, Dakota,, Montana, 

 Kansas. 



Scaphites hippocrepis (De Kay). 

 Plate CVIL, Figs. 3-6. 



1827. Ammonites hippocrepis De Kay, Ann. N. Y. Lye Nat. 



Hist., vol. 2, pp. 273-277, pi. 5, fig. 2(5). 



1828. Scaphites Cuivieri Mort., Jour. Acad. Nat. Sci. Phil., is't 



sen, vol. 6, p. 109, pi. 7, fig. i. 

 1834. Scaphites hippocrepis Mort., Synop. Org. Rem. Cret. Gr. 



U. S., p. 41, pi. 7, fig. I. {S- Cuivieri on plate.) 

 1861. Scaphites hippocrepis Gabb, Synop. Moll. Cret. Form., p. 



88 (32). _ 

 1864. Scaphites hippocrepis Meek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 24. 

 1868. Scaphites hippocrepis Con., Cook's Geol. N. J., p. 730. 

 1892. Scaphites hippocrepis Whitf., Pal. N. J., vol. 2 (Monog. 



U. S. G. S., vol. 18), p. 262, pi. 44, figs. 8-12. 

 1892. Scaphites similis Whitf., Pal. N. J., vol. 2 (Monog. U. S. 



G. S., vol. 18), p. 267, pi. 44, figs. 1-2. 

 1905. Scaphites hippocrepis Johns., Proc. Acad. Nat. Sci. Phil., 



,1905, p. 27. 

 1905. Scaphites similis Johns., Proc. Acad. Nat. Sci. Phil., 



1905, p. 27. 



Description. — Shell subovate in general outline; the living 

 chamber ventricose, rounded on its ventral side, with a decided 



