﻿288 GI.KHULA 



unworn shells, not rayed ; left valve vvitii two pseudocardinals, 

 which are often split up into numerous radiating, nodulous 

 lamelUc, with two remote laterals, the lower the larger ; right 

 valve with two pseudocardinals, the upper small and com- 

 pressed, the lower nmcli si)lit up, and one lateral, which is 

 sometimes slightly douhle ; hinge plate narrowed and rounded 

 in front of the laterals ; beak cavities moderate, not com- 

 pressed, showing numerou.s dorsal scars under the hinge plate; 

 muscle scars large, impressed, smooth, the posterior one semi- 

 circular ; nacre dull purplish. Female shell slightly inflated at 

 posterior base, sometimes having a slight sinuosity behind the 

 swelling. 



Length 95, height 72, diam. 53 mm. 



Length y^i^ height 57, diam. 43 mm. 



Length 80, height 54, diam. 32 mm. 



Louisiana ; eastern Texas ; Rio Grande River ; Escambia 

 County, Florida. 



Type locality, not given. 

 Umo rotimdata Lamakck, An. sans Vert., VL 1819, p. 75. 

 Glebula rotimdata Conrad, Pr. Ac. N. Sci. Phila., 1853, p. 268. 



— Simpson, Syn., 1900, p. 598. 

 Unio rotimdatus Hanlky, IJiv. Shells. 1843, p. 201, pi. xxiii, 



tig. 30. — KusTER, Conch. Cab. Unio, 1861, p. 256, pi. lxxxvi, 



fig. 4. — Reeve, Conch. Icon., X\^L 1865, pl- xxiii, fig. 106. — 



CAI.L, Tr. Ac. Sci. St. Louis, VH, 1895, P- 47, pl- ix- 

 Margarita (Unio) rotmuiatus Lea, Syn., 1836, p. 33; 1838, p. 



Margaron (Unio) rotitiidatiis Lea, Syn., 1852, p. 34; 1870. p. 



55- 

 Unio sidwrhiculata Lamarck, A.n. sans \ ert.. \ L J819. p. 81. 

 Unio siiborbicidatus Fi-rlssac, Guer. ]\Iag.. 1835, p. 26. 

 Unio glebulus Say, Trans. Jl., IV, 1831, p. 526; Am. Conch., 



1832. pl. XXXIV. — Chenu, Bib. Conch., ist sen. Ill, 1845, 



p. 46, pl. XI. fig. 10-12. — SowERRY. Conch. Icon., X\'I, t868, 



pl. EX XIV. fig. 384. 

 Unio subglobosus Lea, Tr. Am. Phil. Soc, V, 1834, p. 30, pl. 



II, fig. 3 : Obs., L 1834. p. 142, pl. II. fig. 3. — SowERRY, Conch. 



Icon., XVJ, 1868, pl. i.xiv, fig. 321. 



