﻿5IO AI.ASMIDONTA 



hind ihciii ; ijuslcrior rid.^c liigli and angled, ending behind in 

 a point near the l)ase ; posterior slo])e somewhat truncated, 

 having two or three low, radial ribs and a few feeble plications ; 

 surface rather smooth ; epidermis tawny to 'greenish-brown, 

 smokv, faintly rayed; left valve with one irregular tooth under 

 the beak, with a vestigial one forward ; right valve with a high, 

 recurved anterior tooth; laterals almost obsolete; beak cavities 

 dee]); nacre l)luish-white. 



Length 40. height ij, diam. 24 mm. 



South Carolina aixl Georgia. 



Type locality, Upper Chattahoochee River ; Columbus ; Pa- 

 lato Creek, Ga. ; Sawney's Creek, S. C. 

 Margaritana triangiilata Le.\. Pr. Ac. N. Sci. Phila., 11, 1858, 



p. 138; Jl. Ac. N. Sci. Phila., IV, 1859. p. 228. pi. xxxii, fig. 



in; Obs.. VIl. 1859, p. 46. ])1. xxxii. fig. iii. — Kustrr, 



Conch. Cab. I'nio, 1862, p. 303, pi. c, fig. 6. 

 Ujiio triangiilata Sowrrhy, Conch. Icon.. XM, 1868, pi. i.xxx, 



fig. 414. 

 MargaroH (Margaritana) triangulata Li<:.\. Syn.. 1870, p. 68. 

 Margaritana triangulatiis P-KTri,, Conch. Sam., III. 1890, p. 



174- 

 Alasriiidonta triangulata Simpson, Syn., T900. p. 672. 



This species shows relationship to . /. arciila by its inflation, 

 its triangular form, beak sculpture and beaks and the some- 

 what sinuous hinge plate. Rut the hinge is heavier and more 

 like that of the ordinary Alasmidontas than that of arcida 

 and the epidermis is that of an Alasmidonta. 



IJnfigured and indeterminate species. 



Margaritana ctowahrnsis Con'RAi-., Pr. Ac. Xat. Sci. Phila.. 1\ . 



1849, p. 154. 

 Alasmodon (Dccuramhis) atropiirpurcinn Rafinesque, Cont. 



Monog., 1831, p. 5. 

 AJasnwdou(nccuvavihis)scnptinn RAi-i\EsorE. Cont., Monog.. 



1831, p. 5. 

 Alasmodon ( Lasini'^ona I 7-iridis I\Ai-i.\'KSorE, Cont.. Monog.. 



i8.V, p. 5- 



