66 PALEONTOLOGY OF NEW JERSEY. 



Family CARDIID.^. 



Genus OAEDIUM Linn. 



Cardium (Cerastoderma) cratiottloides. 



PI. X, figs. 16-1!). 



Cardium craticuloidcs, Conrad: Mioc. Foss., p. 06, PI. xxxvii, fig. 3. 



C. ( Cerastoderma) craticulmdes, Conrad : Proc. Acad. Nat. Sci. Phil., 18G2, p. 570 ; Meek, 



Check List Miocene Foss., p. 8. 

 ? C. laqueatum, Heilpin : Proc. Acad. Nat. Sci. Phil., pp. 398, 400, 403. 



" Suborbicular, ventricose; ribs about twenty-nine, very much com- 

 pressed, protbundly elevated, the summits reflected on botli sides, conse- 

 quently the ribs are as wide on the back as at base; summit of the umbo 

 very prominent. 



" Remarkable for tlie compressed form and great elevation f)f the ribs 

 which are most remote on tlu^ anterior side; ril)s not very regular, but some- 

 what sinuous." (Conrad.) 



The few fragments of Cardium which have been collected from the New 

 Jersey localities are not very satisfactory for study. They are all small, 

 and onlyfragmentsof the larger size shells showing the development of the 

 character of the ribs are found. The small specimens wliich sliow tlu^ apical 

 poi-tion appear to be mostly only the inner shells of the specimens, the outer 

 layers being apparently removed by scnne process, so that the ribs do not 

 present the true features of the species. After a deal of study 1 have come to 

 the conclusion that they do not represent C. Idqmvfiiiii, as has generally been 

 supposed; but that they are more properly referal)l(^ to C. cratictdoides Con- 

 rad. The number of the ribs, their direction, and tlieir form, as seen on the 

 larger fragments, and the want of the posterior flattening of the posterior 

 slope, as seen in G. laqueatum, and lack of obliquity, show this to be the 

 case. I have figured the best fragments wliicli I have examined, and feel 

 certain from the chara,ct(n-s there presente<l that others will agree in this 

 decision. 



Locality and formation : All the fragments seen are from the gray marly 

 layers of the Miocene near Shiloh, or from the more stony layers near 

 Bridgeton, N. J., and are from the collections at Rutgers College or the 

 National Museum. 



