MOLLUSCA. 441 



1 86 1. Ostrea subspatulata Gabb, Synop. Moll. Cret. Form., p. 



210 (154). 

 1864. Ostrea subspatulata MJfeek, Check List Inv. Foss N. A., 



Cret. and Jur., p. 6. 



1868. Ostrea subspatula Con., Cook's Geol. N. J., p. 724. 



1869. Ostrea subspatulata, Coquand, Monog. Gen. Ostrea Terr. 



Cret., p. 43, pi. 15, fig-. 3. 

 1876. Ostrea subspatulata Gabb, Proc. Acad. Nat. Sci. Phil. 



(1876), p. 320. 

 1884. Ostrea subspatulata White, 4th Ann. Rep. U. S. G. $., 



p. 301, pi. 37, figs. 1-2. 

 1886. Ostrea subspatulaita Whitf., Pal. N. J., vol. I (Monog. 



U. S. G. S., vol. 9), p. 32, pi. 3, fig. 14. 



Description. Shell subovate in outline, higher than wide, 

 usually widest below the middle, the dimensions of a nearly com- 

 plete cast of the interior of a lower valve are : length, 45 mm. ; 

 width, 31 mm. Lower valve strongly arcuate longitudinally, the 

 cast nearly smooth or with a few obscure concentric undulations, 

 the muscular impression large, situated in the lower left-hand 

 quarter of the cast. The impressions of the exterior of the shell 

 show rather strong concentric undulations. 



Remarks. In New Jersey this species is only known in the 

 formi of casts, none of which have been observed to attain so 

 large dimensions as some of the examples from the South. The 

 most characteristic feature of the species is its strongly arcuate 

 form longitudinally, a feature which is even more conspicuous in 

 the shell itself than in the casts because of the great thickening of 

 the shell in its central part. 



Formation and 'locality. Wenonah sand, near Crawfords 

 Corner (i26 3 ); near Marlboro (I3O 1 ). 



Geographic distribution. New Jersey, Georgia. 



Ostrea crenulimarginata Gabb. 

 Plate XLIL, Figs. 12-13. 



1860. Ostrea crenulimarginata Gabb, Jour. Acad. Nat. Sci. 



Phil., 2d ser., vol. 4, p. 398, pi. 68, figs. 40-41. 



1 86 1. Ostrea crenulimarginata Gabb, Synop. Moll. Cret. Form., 



p. 208 (152). 



