SHUMARD—CRETACEOUS FOSSILS. 599 
show the hinge, and I am therefore in some doubt as to 
whether it properly belongs with the above genus or Cytherea. 
Form. and Locality—Grayson County, five miles north of 
Sherman, associated with Scaphites vermiculus, in Septaria of 
the Marly clay, near the base of the Lower Cretaceous. 
Collected by Dr. G. G. Shumard. 
GENUS CARDIUM. 
C. CHOCTAWENSE, 0. sp. 
Locality.—Post-Oak Creek, Grayson County, associated 
with Ostrea bellarugosa 
this is a rare shell and quite distinct from any species 
known to me from the Cretaceous strata of the United 
States. Collected by Dr. G. G. Shumard. 
C. CoLORADOENSE, n. sp. 
and s] ? mbonial region gibbous superiorly, 
Fonaded 15 inferiorly to the pallial margin; buce 
Length and width, 0.60 of an inch; thickness, 0.46. 
This sh 
ell is quite characteristic of the superior part of our 
PA aM? ety Tue el Be es bat ey eee Se Pee stl ie aE lll caida ea te 
rao ila A 
pe 
