136 BUI.I.ETIN 31 13^ 



de Greg, though not equally thick. On the Neuse River, N. C. 

 the large neusensis with its incrassated interior, powerful hinge 

 and generally biangulate pallial sinus is extremely abundant in 

 the form of casts. The Claiborne brings forth the typical per- 

 ovata in great abundance. It shows a tendency fore and aft to 

 even, well-defined concentric corrugation and passes into variety 

 aldrichi. One off-shoot becomes decidedly corrugate and returns 

 to the primitive flattish state and has received the name mortoni. 

 In the Jackson the subvitrea form is known as annexa ; the ald- 

 richi, aspeai'lensis. 



Meretrix sylvserupis, n. sp., PI. 43. Fig. i. 



C. perovafa} Aid., Bull, i, Geol. Surv. Ala., 1S86, p. 53. 

 M. subimpressa var. Har. These Bulletins, vol. 2, 1897, p, 255, pi. 18, 

 figs. 6, 7. 



The general characteristics of this form have already been 

 discussed. With a much greater amount of material containing 

 all stages of growth of subimpressa it is evident the two species 

 are quite distinct. Vi^xxres oi sjibimpressa (figs. 2 and 3), from 

 Pope's Creek, Md., are here introduced for comparison with this 

 Woods Bluff, Sabine, form. It is also clear that this merges, 

 through the St. Maurice var. lisbonensis into perovafa oi the Clai- 

 borne sands. 



Types. — (The two specimens figured on pi. 18, vol. 2, of 

 these Bulletins ; in C. U. Mus.) 



Horizon. — Sabine Eocene, upper beds. 



Specimen figured. — Paleont. Mus. Cornell Univ. 



Locality. — Woods Bluff, Ala. 



Meretrix neusensis, n, sp., PI. 43. Figs. 4-7, 10. 



Specific characterization. — General appearance as figured ; 

 nearly smooth centrally, somewhat undulate peripherally ; rather 

 longish, at some localities, with exceedinglj^ thick shell in the 

 umbonal regions but thin basally ; interior of the shell not ca- 

 pacious, not extending up into the beaks behind the cardinal 

 plate ; hinge heavy, broad. 



