66 PALEONTOLOGY OF NEW JERSEY. 
Family CARDIID2. 
Genus CARDIUM Linn. 
CARDIUM (CERASTODERMA) CRATICULOIDES. 
PI. x, figs. 16-19. 
Cardium eraticuloides, Conrad: Mioc. Foss., p. 66, Pl. xxxvm, fig. 3. 
0. (Cerastoderma) craticuloides, Conrad: Proc. Acad. Nat. Sci. Phil, 1862, p.576; Meek, 
Check List Miocene Foss., p. 8. 
? CO. laqueatum, Heilpin: Proc. Acad. Nat. Sci. Phil., pp. 398, 400, 403. 
‘“Suborbicular, ventricose; ribs about twenty-nine, very much con 
pressed, profoundly elevated, the summits reflected on both sides, conse- 
quently the ribs are as wide on the back as at base; summit of the umbo 
very prominent. 
“Remarkable for the compressed form and great elevation of the ribs 
which are most remote on the anterior side; ribs 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 only fragments of the larger size shells showing the development of the 
character of the ribs are found. The small specimens which show the apical 
portion appear to be mostly only the inner shells of the specimens, the outer 
layers being apparently removed by some process, so that the ribs do not 
present the true features of the species. After a deal of study I have come to 
the conclusion that they do not represent C. laqueatum, as has generally been 
supposed; but that they are more properly referable to C. craticuloides Con- 
rad. The number of the ribs, their direction, and their form, as seen on the 
larger fragments, and the want of the posterior flattening of the posterior 
slope, as seen in C. laqueatum, and lack of obliquity, show this to be thie 
case. I have figured the best fragments which I have examined, and feel 
certain from the characters there presented that others will agree im 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. 
