MIOCENE JMOLLUSCA AND CEUSTACEA. ' 5? 



of the inner maro'in entirely worn Mwav. Some of them, however, show 

 the surface Aery perfectly preserved, and the hing-e and other characters 

 beautifully distinct. The plications of the exterior surface are low- 

 rounded, hut still \ cr^' distinct, and the transverse strial tine, rather even, 

 and well marked, the entire characters corresponding well with those of 

 shells of the species from th<' Yoi-ktown, Va., and Maryland beds, except 

 in the smaller size. The shells are evidently only partially orown. 



Foriiiatio)! (ind local it//: All those oliserved are from the artesian well 

 of Mr. Woolman, at Atlantic City, N. ,1., and are from the cabinet of the 

 Acadeni)- of Natural Sciences, Phibuhdiihin. 



Genus (JAJIDITAMERA (Joiiracl. 

 Oaruitamera akata. 

 Plate IX, tigs. r> and (i. 



Carditamera arata Conrad: Foss. Sliells of tlie Tert. Form., p. 20, PI. v, fig. 1; Foss. 



Med. Tert., p. 11, PI. Vi, tig. 2; Oat. Miocene Foss. Atlantic Sloi)e. Proc. A. N. 



S. Phil., 18(i2, p. 579; Meek, Check List Miocene Foss., p. 7. 

 Compare ('. aculeaUt C(ni.: Aui. Jour. Conch., vol. 2, p. 73, PI. iv, tig. 5. 



Mr. Conrad's description of this species in the Fossils of the Median 

 Tertiary Formations is as follows: "Shell trapezoidal, with about hfteen ribs, 

 pi-ofoundly prominent, and ci-ossed with crowded, arched, and somewhat 

 squamose stria' ; three of the ribs on the jiosterior side larger than the others: 

 dorsal margin slightly declining, straight; posterior margin obli(|uely trun- 

 cated; extremity rounded; the margin dilated at the extremit}' of the three 

 large ribs; margin within profoundly dentate posteriorly." 



The specimen which he figures is probably from ilaryland, or some 

 more southern localit}-. There are some features of the New Jersey speci- 

 mens which, although coming within the limits of his description, do not cor- 

 respond to his figure, and the number of plica? do not agree with either. His 

 figure gives the hinge line and base as parallel, although his description 

 says the "dorsal margiil slightly declining." On the New Jersey shells the 

 dorsal margin declines considerably, and the shell has eighteen to twenty 

 ribs, generally twenty. The New Jersey shells, so far as I have seen them, 

 are all much narrower in pro])ortion from beak to l)ase than his fig'ure, and 



