178 PALEONTOLOGY OF NEW JEESEY. 



of the casts, unless it be in the absence of the internal rib, which is described 

 as occurring in the right valve of some specimens of that genus, bordering 

 the muscular impression. Prof Agassiz refers Corimya to the Isocardes, but 

 its affinities are certainly with Anatma, as they have been placed by later 

 authors. 



Formation and locality, — In the Lower Green Marls at MuUica Hill and 

 Holmdel, New Jersey. 



Genus CEECOMYA Agassiz. 



Cercomya peculiaris. 

 Plate XXIII, Figs. 24 and 25. 



Inoceramus peculiaris Conrad. Am. Jour. Conch., Vol. Y, p. 43, PL I, Fig. 13. 

 Cercomya peculiaris Conrad. Am. Jour. Conch., Yol. YI, p. 76. 



A single fragment of a cast of one valve only has been seen of this 

 species, and that altogether too imperfect to afford means for positive ge- 

 neric reference. The form somewhat resembles species of Cercomya Agassiz, 

 but is by no means unquestionable, and is fully as much like Thracia. 

 The form has been subtriangular, with an obliquely truncated anterior end, 

 slightly gaping; the posterior part of the shell more elongated, slightly 

 curved, and more widely gaping. Valves moderately convex and strongly 

 furrowed concentrically. On the left valve there is evidence of a propor- 

 tionally wide hinge-plate, with a large deep ligamental cavity beneath the 

 apex. No evidences of teeth or teeth-like projections are preserved, as only 

 the impression of the under surface of the plate is shown. 



Formation and locality. — In the lower portion of the Lower Green Marls 

 at Crosswicks, New Jersey. 



CORBULID^. 



Genus COEBULA Brugui^re. 



Corbula crassiplica. 



Plate XXIII, Fig. 30. 



Corhula crassiplica Gabb. J. A. K. Sci., new ser., Yol. lY, p. 394, PL LXYIII, Fig. 25. 



Synopsis, p. 110. Meek, Check-list, p. 15. Geol. Surv. K J., 3868, p. 727. 

 Corhula perbrevis Conrad. Kerr's Geol. Eept. N. Car., Appendix, p. 17, PI. II, Fig. 5. 



The shells upon which this species is identified from New Jersey are 

 very small, scarcely exceeding a fourth of an inch in length, the height 



