718 PllOCEEDIXGS OF THE XATIONAL MUSEUM. VOL.XXH. 



fUNIO ARCTATUS var. TORTIVUS Lea. 



* t Unio tortirus LEA/ Pr. Am. Phil. Soc., 1, 1840,p. 287 ; Tr. Am. Phil. Soc.,VIII, 1842, 



p. 204. pi. xii, iig. 17 ; Obs., Ill, 1842, p. 42, pi. xn, fig. 17. 'CONRAD, Pr. Ac. N. 

 Sci. Phila.,VI, 1853, p.259. H. and A. ADAMS, Gen. Rec. Moll., II, 1857,p.493. 

 * CHEXU, 111. Conch., 1858, pi. xxix, figs. 6, 6a, 66.* SOWEKBY, Conch. Icon., 

 XVI, 1866, pi. xxxvi, fig. 193.* B. II. WRIGHT, Check List, 1888.* P.KTEL, 

 Conch. Sam., Ill, 1890, p. 169. * SIMPSON, Pr. U. S Nat. Mas., XV, 1892, p. 

 421, pi. LXIII, fig. 8; LXIV, figs. 1, 3, 4. 

 *Margaron ( Unio) tortivus LEA, Syn., 1852, p. 33; 1870, p. 53. 



* t Unio tetricus LKA, Pr. Ac. N. Sci. Phila., IX, 1857, p. 170; *J1. Ac. N. Sci. Phila., 



IV, 1859, p. 195, pi. xxn, fig. 78; " Obs., VII, 1859, p. 13, pi. xxn, Iig. 78. 

 KUSTER, Conch. Cab. Unio, 1862, p. 276, pi. xci, fig. 7 ; xcm, fig. 3.* B. H. 

 WRIGHT, Check List, 1888. *P,ETEL, Conch. Sam., Ill, 1890, p. 169. 

 *Maryaron ( Unio) letricus LEA, Syn., 1870, p. 53. 



* \Unio puri>nrellm LEA, 2 Pr. Ac. N. Sci. Phila., IX, 1857, p. 171; Ml. Ac. N. Sci. 



Phila., IV, 1859, p. 19, pi. xxni, fig. 81; *Obs., VII, 1859, p. 16, pi. xxm, 

 fig. 81." B. H. WRIGHT, Check List, 1888. 



* Margaron ( Unio) piirpureUus LEA, Syn., 1870, p. 53. 



*t Unio merceri LEA, Pr. Ac. N. Sci. Phila., VI, 1862, p. 169; Ml. Ac. X. Sci. 

 Phila., V, 1862, p. 209, pi. xxxi, fig. 278; "Obe., IX, 1863, p. 31, pi. xxxi, 

 fig. 278. *B. H.WRIGHT, Check List, 1888. *P.ETEL, Conch. Sam., Ill, 

 1890, p. 159. 



* Margaron ( Unio) merceri LEA, Syn., 1870, p. 61. 



Florida; South Georgia; the type west to the Black Warrior Eiver, 

 Alabama. 



tUNIO NIGELLUS Lea. 



* Unio nigellus LEA, Pr. Am. Phil. Soc., V, 1852, p. 251 ; * Tr. Am. Phil. Soc., X, 1852, 



p. 283, pi. xxiv,fig.42; *0bs., V,1852, p. 39, pi. xxiv, fig. 42. *CoNRAD,Pr. 

 Ac. N. Sci. Phila., VI, 1853, p. 253. *H. and A. ADAMS, Gen. Rec. Moll., II, 

 1857, p. 494. *B. H.WRIGHT, Check List, 1888. *P.ETEL, Conch. Sam., 

 Ill, 1890, p. 161. 



* Margaron ( Unio) nigellus LEA, Syn., 1852, p. 30; 1870, p. 53. 



*t Unio denigratus LEA, Pr. Ac. N. Sci. Phila., IX, 1857, p. 171; * Jl. Ac. N. Sci. 

 Phila., IV, 1859, p. 200, pi. xxni, fig. 83; *Obs., VII, 1859, p. 18, pi. xxni, 

 fig. 83.' B. H. WRIGHT, Check List, 1888.* SIMPSON, Pr. U. S. Nat. Mus., 

 XV, 1892, p. 422, pi. LXV, fig. 1. 



*Margaron (Unio) denigraius LEA, Syn., 1870, p. 52. 



Chattahoochee River system: south into Florida. 



t UNIO PINEI B. H. Wright. 



*Unio pinei B. H. WRIGHT, Naut., XI, 1897, p. 40." SIMPSON, Pr. Ac. N. Sci. 

 Phila., 1900, p. 80, pi. in, fig. 1. 



North Florida. 



1 Unio arctatus is a widely distributed, abundant, and variable species, ranging 

 from the Black Warrior River to southern Florida. I have examined a great amount, 

 of material from the Black Warrior and Cahawba rivers (collected by Call), from 

 the Flint and Chattahoochee rivers from the Lea and other collections, and I feel 

 reasonably sure that all the species I have united should <> together. 



2 1 believe this to be a small, somewhat inflated form of urctatun. 



