568 CRETACEOUS PALEONTO'LOGY. 



ever, appears much more slender in its proportions than the 

 species known from Texas and other southern localities, as well 

 as more strongly enrolled." (Whitfield.) 



Remarks. — ^The type specimen of this species is the only ex- 

 ample which has been observed, the species not having been met 

 with in the recent collections of the Survey. 



Formation and locality. — Navesink marl, Bruere's marl pit, 

 near Walnford (Whitfield). 



Geographic distribution. — New Jersey. 



Family OAPRINIDAB 



Genus Caprotina d'Orbigny. 



Caprotina jerseyensis n. sp. 



Plate LXII., Figs. 13-13. 



Description. — The type specimen with a maximum length of 

 21.5 mm., a width of 13 mm., and a depth of 15 mm. Beaks 

 curving to the left. Lower valve much deeper than the upper, 

 attached by nearly one-half its entire surface, the beak projecting 

 far beyond that of the upper valve. Upper valve moderately 

 convex. The shell substance is preserved only on a portion of 

 the upper, valve where the surface markings are seen to be very 

 narrow but rather highly elevated, sharp, radiating costse, the 

 interspaces being twice as wide as the ribs ; the radiating mark- 

 ings are crossed by very fine concentric lines of growth. On 

 the internal cast both the radiating and concentric markings are 

 faintly impressed. 



Remarks. — This species is founded upon a single individual 

 preserving both valves. It is for the most part a cast of the 

 interior of the shell, but a portion of the shell itself is preserved 

 upon the upper valve, and sufficient fragments of the shell are 

 still preserved upon the lower valve to show that the surface 

 markings were essentially the same on both. The specimen is 

 nearly complete, the beak only of the lower valve being injured. 

 The species should be compared with Caprotina cenomanensis 

 d'Orbigny,^ from the Upper Cretaceous of France. 



' Pal. Franc, Terr. Cret., vol. 4, p. 261, pi. 595, figs. 1-4. 



