6oo CRETACEOUS PALEONTOLOGY. 



1868. Buchardia conradi Con., Cook's Geol. N. J., p. 726. 

 1886. Isocardia conradi Whitf., Pal. N. J., vol i (Monog. U. S. 



G. S., vol. 9), p. 200, pi. 26, figs. 3-4. 

 1905. Isocardia conradi Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), p. 15. 



Description. — The dimensions of the type specimen are : length, 

 35 mm. ; height, 30 mm. ; thickness, 26.5 mm. Shell subtriangular 

 in lateral view and cordate in front view. Beaks much elevated 

 and enrolled, situated in front of the middle of the shell. Antero- 

 cardinal margin long and concave, sloping steeply; anterior 

 margin short, sharply rounded; basal margin long, rather strongly 

 convex through the greater part of its length, becoming concave 

 near its posterior extremity; postero-basal extremity acutely 

 subangular ; posterior and post-cardinal margins continuous, very 

 long, gently convex, sloping steeply from the beaks to the 

 postero-basal angle. Valves strongly ventricose, with an angular 

 umbonal ridge subparallel with the post-cardinal margin; post- 

 cardinal slope steep; in front of the umbonal ridge is a slight 

 sinus becoming more conspicuous towards the ventral margin, in 

 front O'f the sinus the surface is somewhat regularly convex 

 through the central part of the valve, with the anterior slope 

 abrupt and somewhat inflected to the antero-cardinal margin. 

 Surface oi cast marked by concentric lines. 



Remarks. — This species has not been met with in the recent col- 

 lections of the Survey, but it was reported from Timber Creek 

 by Gabb, at the time o>f his original description oi the species. 

 The type specimen in the collection of the Philadelphia Academy 

 of Science is labeled as coming from Alabama, but its lithologic 

 characters resemble the Timber Creek fossils, rather than those 

 from any of the Alabama localities, and it is possible that the 

 lable is incorrect. 



Formation and locality. — Vincentown limesand, Timber Creek 

 (Gabb). 



Geographic distribution. — New Jersey ? 



