NO. 1205. SYNOPSIS OF THE NJIADES— SIMPSON. 793 



tQUADRULA EBENUS Lea. 



*Z7moe&ewM,sLEA,Tr.Aru. Phil. Soc.jIV, 1831,p.84,pl. ix. fig. 14; *Obs., I,1834,p, 

 94, pi. IX, fig. 14.— ^Conrad, New F. W. SLells, 1834, p. 69.— * Hanley, Test. 

 Moll., 1842, p. 202; *Biv. Shells, 1843, p. 202, pi. xx, fig. 47.— * Catlow and 

 Eeeve, Conch. Nora., 1845, p. 58. — *H. and A. Adams, Gen. Eec. Moll., II, 1857, 

 p. 492; — *Chenu, 111. Conch., 1858, pi. xv, figs. 7, 7a, 7b. — * Sowerby, Conch. 

 Icon., XVI, 1868, pi. i.xvi, fig. 334.— *Calkins, Pr. Ottawa Acad. Set., 1874, p. 

 42.— * B. H. Wright, Check List, 1888.— "P.etel, Conch. Sam., Ill, 1890, 

 p. 151. 



"^Margarita ( Unio) ebenus Lea, Syn., 1836, p. 34; 1838, p. 23. 



^Margaron ( Unio) ebenus Lea, Syn., 1852, p. 35; 1870, p. 56. 



* Unio ohovaUs Say, Ara. Conch., VI, 1834. 



* Unio obliquus Conrad, Monog., IX, 1837, p. 77, pi. xliii, fig. 2.—* KusTER,Conch, 



Cab. Unio, 1861, p. 215, pi. lxxi, fig. 4. 



* Unio mytiloides Swainson, Treatise on Mai., 1840, p. 270, figs. 52, 53. 



Mississippi drainage generally except its western portion; Alabama 

 and Tombigbee rivers; northeast Texas! 



tQUADRULA GLOBATA Lea. 



* Unio ghbatus Lea, Pr. Ac. N. Sci. Phila., I, 1871, p. 191; * Jl. Ac. N. Sci. Phila., 



VIII, 1874, p. 5, pi. I, fig. 1 ; * Obs., XIII, 1874, p. 9, pi. i, fig. 1.—* B.H.Wright, 

 Check List, 1888. 



Holston and Tennessee rivers, Tennessee; Etowah Eiver, Georgia. 



(Group of Quadrula glandaceaJ) 



Shell rhomboid-oval, nearly straight below and slightly biangulate 

 behind, with a well-dellued double posterior ridge; beaks probably 

 full; surface slightly and irregularly sulcate; epidermis wrinkled, 

 tawny; hinge strong, the plate somewhat flattened; pseudocardinals 

 triangular; laterals strong, secondary lateral of right valve well devel- 

 oped; beak cavities deep, compressed; muscle scars very deep, smooth; 

 nacre dirty straw color. 



tQUADRULA GLANDACEA Lea. 



* Unio glandaceus Lea, Pr. Ac. N. Sci. Phila., V, 1861, p. 59 ; *J1. Ac. N. Sci. Phila., 



V, 1862, p. 77, pi. IX, fig. 226; ^Obs., VIII, p. 81, pi. ix, fig. 226.— * B. H. 

 Wright, Check List, 1888. 



* Mar gar on ( Unio) glandaceus Lea, Syn., 1870, p. 38. 



Coosa and Oahawba rivers, Alabama. 



II am somewhat at a loss to know where to place this group. The very limited 

 amount of material I have seen is in a badly eroded condition. I can form no 

 idea of the beak sculpture, and I have never seen the soft parts. The texture and 

 coloring of all the shells I have seen are like those of Pleurobema, but the very 

 deep beak cavities and the general form are like Quadrula. 



