726 CRETACEOUS PALEONTOLOGY. 



Triton praecedens Whitfield. 

 Plate LXXXIV., Figs. 7-8. 



1892. Triton (Epidromus} prcecedens Whitf., Pal. N. J., vol. 2 

 (Monog. U. S. G. S., vol. 18), p. 58, pi. 5, figs. 6-7. 



Description. "Shell small and moderately slender, spire 

 elevated, longer than, or about equal to, the length of the body 

 volution and anterior beak, as viewed from the back of the shell ; 

 apical angle of the spire between 30 and 35; volutions quite 

 ventricose, with strongly marked sutures ; principal varices occur- 

 ing at about every two- thirds O'f a volution, but with secondary 

 varices between, visible on the casts but not definitely enough to 

 give a positive idea of their exact number, yet apparently three 

 on the body volution ; each of the principal varices marked by 

 about seven well defined depressions on the back, indicating that 

 number of spiral ridges on the shell and protuberances on the 

 inner margin of the lip ; aperture of medium size, semi-lunate, the 

 outer lip only moderately expanded ; columella slender, and 

 anterior beak of moderate length ; number of volutions not 

 definitely ascertained, as the specimens are imperfect." (Whit- 

 field.) 



Remarks. This species is known only from the Navesink marl, 

 but it is not one of the common members of the fauna of that 

 formation. The species may be recognized by the impressions of 

 the internal varices of the shell upon the surface of the internal 

 casts. 



Formation and locality. Navesink marl, near Walnford 

 (149), near Jacobstown (150), Mullica Hill (Whitfield). 



Geographic distribution. New Jersey. 



Genus TRACHYTRITON Meek. 



There is much doubt as to the correct generic position of the 

 species which were described by Whitfield as members of the 

 genus Trachytriton. They are only known from the internal 

 casts, and for want of any definite knowledge of their true generic 

 characters, they will be allowed to remain where Whitfield has 



