598 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii. 



with a straight edge in front 5 dorsal scars numerous, distinct, placed 

 back of the pseudocardinals ; cavity of the beaks not deep or com- 

 pressed ; nacre dull lurid to purplish brown. 



Animal with gills nearly equal in size, inner slightly the larger in front, 

 united the whole length to the abdominal sac; ovisacs apparently 

 separated from each other by a sulcus as in Lampsilis; palpi very large, 

 wide, wrinkled; mantle having a wide, slightly thickened border, double 

 edged, the inner being beautifully toothed ; branchial opening papillose; 

 anal crenulate; foot small; whole animal the color of the nacre. 



tGLEBULA ROTUNDATA Lamarck. 



* Unio rotundata Lamarck, An. sans Vert., VI, 1819, p. 75. — *Lea, Obs., 1, 1834, p. 



201. 

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



* Unio rotiindatus Hanley, Test. Moll., 1842, p. 201; *Biv. Shells, 1843, p. 201, pi. 



XXIII, fig. 30.— *Catlow and Reeve, Conch. Norn., 1845, p. 63. — *Conrad, Pr. 

 Ac. N. Sci. Phila., VI, 1853, p. 257.— *H. and A. Adams, Gen. Rec. Moll., II, 

 1857, p. 492.— *Kuster, Conch. Cab. Unio, 1861, p. 256, pL Lxxxvi, fig. 4.— 

 "Reeve, Conch. Icon., XVI, 1865, pi. xxiii, fig. 106.— *B. H. Wright, Check 

 List, 1888.— *P^TEL, Conch. Sam., Ill, 1890, p. 166.— *Call, Tr. Ac. Sci. St. 

 Louis, VII, 1895, p. 47, pi. ix. 



* Margarita {Unio) rotundatus Lea, Syn., 1836, p. 33; 1838, p. 23, 

 *Margaron ( Unio) rotundatus Lea, Syn. 347, 1852, p. 34; 1870, p. 55. 



* Unio suhorhiculata Lamarck, An. sans Vert., VI, 1819, p. 81. — *Lea, Obs., 1, 1834, 



p. 201.— *Deshayes, An. sans Vert., 2d ed., VI, 1835, p. 546; 3d ed., II, 1839, p. 

 671. 



* Unio suiorbiculatus Ferussac, Guar. Mag., 1835, p. 26. 



Unio glehulus Say, Transylvania Jl., IV, 1831, p. 526.— Say, Am. Conch., No. IV, 

 1832, pi. XXXIV ; No. V, 1832, p. 4 (of cover).— Conrad, New F. W. Shells, 

 1834, p. 69.— Chenu, Bib. Conch., 1st ser.. Ill, 1845, p. 46, pi. xi, figs. 10-12.— 

 SowERBY, Conch. Icon., XVI, pi. Lxxiv, fig. 384. 



''Unio glebulus P^tel, Conch. Sam., Ill, 1890, p. 154. 



*Unio sulglohosus Lea, Tr. Am. Phil. Soc, V, 1834, p. 30, pi. 11, fig. 3; *0b8., I, 

 1834, p. 142, pi. II. fig. 3.— *SoWERBY, Conch. Icon., XVI, 1868, pi. lxiv, fig. 

 321. 



""Unio granadensis Conrad,i pr. Ac. N. Sci. Phila., VII, 1855, p. 256.— *B. H. 

 Wright, Check List, 1888. 



Louisiana; eastern Texas; Eio Grande River; Escambia County, 

 Florida. 



1 Conrad says it is suboval, with the disks somewhat flattened, with minute, radiat- 

 ing lines extending to the tips of the beaks. The rotundata sometimes shows radi- 

 ating ridges at the beaks in eroded specimens. He also states that the nacre of his 

 species is purple. The description therefore fits Lamarck's species perfectly, 

 though I have never known the species to come from so far west as the Rio Grande — 

 Conrad's locality. 



