64 BULI.KTIN 31 ^4 



Leda magnopsis, n. sp., PI. 24. Fig. 8. 



In a coquina-like rock labelled "Rock Swamp" a few miles 

 south-east of Springfield, S. C, is found a fragmentary Leda 

 which we took at first to be Idea's Z.. magna. But instead of 

 having a smooth radial band extending down the post-umbonal 

 slope as in magna and in lisboiiensis, the concentric liration swings 

 over this area but little diminished in strength. Just behind, 

 there is a deep radial furrow, but the concentric or diagonal lin- 

 ing is not to be seen between this furrow and the margin of the 

 shell as in lisboiiensis or Idea's species. 



Type. — Paleont. I^ab. Cornell Univ. 



Leda basiropensis, PI. 24. Figs. 9, 10. 



Leda bastropensis Harris, Proc. Phila. Acad. Nat. Sci. 1895, p. 46, pi. i, 



fig- 3- 

 Leda bastropensis Y)a\\, Trans. Wag. &c., '95, p. 578. 



Harrises originoJ description. — General form as figured ; medial por- 

 tions of the valves with regular, strong, concentric strise ; striae obsolete on 

 the anterior end and on the post-umbonal slope, the latter with a shallow 

 furrow extending from the umbo to near the extremity of the valve ; within 

 the valve a raised line or ridge, emanating from the umbonal region and ex- 

 tending along beneath the hinge finally terminates in the middle of the pos- 

 terior end and is there slightly enlarged. 



This species differs from L. plicata L,ea in its lack of striation over 

 portions of the exterior, and the more central positions of the umbones. 

 From L . mater Mr. , bastropetisis is distinguished by its want of anterior rad- 

 iating Isulci, its lack of post-umbonal striation and by its form. This is 

 readily distinguished from L. albirupina Har., since it lacks the smooth, 

 Yoldia-like aspect about the umbones so characteristic of that species. 



Type and specimen figured. — Univ. Tex. Coll. 



Localities and horizo7i. — St. Maurice stage at Starr-Zapata 

 Co. line on the Rio Grande ; and i mile below Milam-Burleson 

 Co. line, Brazos River, Tex. ; Ft. Gaines, Ga. ? 



Leda bella Conrad, PI. 24. Figs. 11-16. 



Nucuta bella Con., A. J. S., 1833, vol. 33, p. 343. 



NuciUa plicata Lea, Cont. to Geol., 1833, p. 85, pi. 3, fig. 64. 



Leda bella Con., Proc. Phila., Acad., 1854, p. 29. 



N7i,c7ilana plicata Con., Am. Jr. Conch., vol. i, 1865, p. 13. 



Leda plicata de Greg., Faun. Ala., '90, p. 189, pi. 23, figs. 6-10. 



Nuculana plicata Cossm., Notes Compl. '93, p. 15. 



