MOLLUSCA. 641 



Renmrks. — The specimen which has been used as the basis for 

 the preceding description is a very perfect internal cast with the 

 accompanying natural mould of the exterior from which a cast 

 has been taken to show the external features of the shell. , This 

 cast has the right valve complete except for a slight restoration 

 along the ventral margin, the left valve being less complete. This 

 specimen has been compared with the type of the species, which 

 has never been illustrated, and the agreement is close except that 

 the specimen here illustrated is larger. The casts of this species 

 somewhat resemble those of C. bisulcata, but the central portion 

 of that species is much more inflated, with more deeply impressed 

 muscular impressions. Whitfield's illustration of C. subcom- 

 pressa, on comparison with the type of that species, proves tO' be 

 entirely different, and the specimen from which it was drawn is 

 • believed toi be an example of C. foulkei. 



Pormaiion and locality. — Woodbury clay, near Matawan 

 (103), near Haddonfield (183). 



Geographic distribution. — ^New Jersey. 



Corbula crassiplica Oabb. 

 Plate LXXII., Figs. 27-28. 



i860. Corbula crassiplica Gabb, Jour. Acad. Nat. Sci. Phil., 2nd 



sen, vol. 4, p. 394, pi. 68, fig. 25. 

 1 861. Corbula crassiplica G&.bb, Synop. Moll. Cret. Form., p. 



166 (no). 

 1864. Corbula crassiplicata Mieek, Check List Inv. Foss. N. A., 



Cret. and Jur., p. 15. 

 1868. Corbula crassiplicata Con., Cook's Geol. N. J., p. 727. 

 1875. Corbula perbrevis Con., Kerr's Geol. N. Car., App., p. 11, 



pi. 2, fig. 5. 

 1886. Corbula crassiplica Whitf., Pal. N. J., vol. i (Monog. 



U. S. G. S., vol. 9), p. 178, pi. 23, fig. 30. 



Description. — The dimensions of 'a right valve are : length, 6 

 mm. ; height, 5 mm. Shell subtriangular in form. Beaks large, 

 inflated and enrolled, situated a little in front of the middle of the 



41 PAI, 



