NO. 1205. SYNOPSIS OF THE NAIADES— SIMPSON. 707 



Gen. Rec. Moll., II, 1857, p. 495.— * Calkins, Pr. Ot. Ac. Sci., 1874, p. 42.— 



* B. 1 1 . Wright, Check List, 1888.—* P.etel, Coach. Sam., Ill, 1890, p. 149.— 



* Call, Tr. Ac. Sci., St. Louis, VII, 1895, p. 12, pi. ii. 



* Margarita ( Unio) crassidens Lea, Syn., 1836, p. 19; 1838, p. 17. 

 ""Margaron ( Unio) crassidens Lea, Syn., 1852, p. 24; 1870, p. 37. 



*f {Jnio nigra Eafixesque, Ann. Gen. Sci. Brux., V, 1820, p. 291, pi. lxxx, figs. 1-4. 



* Unio niger Say, Am. Conch., VI, 1834.—* Conrad, New F. W. Shells, 1834, p. 70.— 



*Ferussac, Guer. Mag., 18.35, p. 27.— * Conrad, Monog., VI, 1836, p. 49, pi. 



XXVI. — * KuSTER, Conch. Cab. Unio, 1852, p. 25, pi. iv, fig. 1. — * Agassiz, Arch. 



fiir Naturg., I, 1852, p. 50.— * Conrad, Pr. Acad. N. Sci , Phila., VI, 18,53, p. 



253.—* SowERBY, Conch. Icon., XVI, 1868, pi. lxxviii, fig. 408. 

 *? Unio cuneat IIS Barnes, Am. Jl. Sci., VI, 1823, p. 263.— * Hildreth, Am. Jl. 



Sci., XIV, 1828, p. 279, fig. 3.—* Short and Eaton, Transylvania JL, 1831, 



p. 78. 

 *Mya cuneaia Eaton, Zool. Text Book, 1826, p. 220. 

 *.^ Unio discus Sowerby, Conch. Icon., XVI, 1868, pi. lxii, fig. 310. 

 *Uniocrassus Sowerby, Conch. Icon., XVI, 1868, pi. xcv, fig. 520. 



Mississippi drainage generally; Alabama and Tombigbee rivers; 

 southeast to the Chattahoochee River. In the southeastern part of 

 its range this species seems to merge into TJ. incrassatus. 



fUNIO INCRASSATUS Lea.i 



*f7TOoiwcra,9sa«ttsLEA, Pr.Am. Phil. Soc, 1, 1840, p. 286; *Tr.Am.Phil. Soc.,VIII, 

 1840, p. 217, pi. xvi, fig. 34; * Obs., Ill, 1842, p. 55, pi. xvi, fig. 34.—* H. and 

 A. Adams, Gen. Eec. Moll., II, 1857, p. 495.— *Chenu, 111. Conch., 1858, pi. 

 XXX, figs. 5, 5a, 5t. — *Kuster, Conch. Cab. Unio, 1861, p. 192, pi. lx, fig. 5. — 



* Reeve, Conch. Icon., XVI, 1865, pi. xxvi, fig. 127.— *B. H. Wright, 

 Check List, 1888.— *PiETEL, Conch. Sam., Ill, 1890, p. 155. 



^Margaron {Unio) incrassatus Lea, Syn., 1852, p. 24; 1870, p. 37. 



Coosa Eiver system; Chattahoochee and rivers of north Florida; 

 east to Savannah !. 



tUNIO POLYMORPHUS B. H. Wright. 



* Unio polymorphus B. H. Wright, Naut., XIII, 1899, p. 42. 



Spanish Creek, Charlton County, Georgia. 



tUNIO FORBESIANUS Lea. 



* Unio forhesianus Lea, Pr. Am. Phil. Soc, V, 1852, p. 251; *Tr. Am. Phil. Soc, 



X, 1852, p. 264, pi. XVI, fig. 17 ; * Obs., V, 1852, p. 20, pi. xvi, fig. 17.—* Conrad, 

 Pr. Acad. Nat. Sci. Phila., VI, 1853, p. 249.— *H. and A. Adams, Gen. Eec. 

 Moll., II, 1857, p. 495.— * KusTER, Conch. Cab. Unio, 1861, p. 310, pi. LXix, 

 fig. 6.— *MusGKAVE, Phot. Conch., 1863, pi. ii, fig. 2. — * Sowerby, Conch. 

 Icon., XVI, 1868, pi. Lxxi, fig. 361.— *B. H. Wright, Check List, 1888.— 



* Simpson, Pr. U. S. Nat. Mns., XV, 1892, p. 410, pi. xlix, fig. 3; l, figs. 2, 3, 

 *Margaron {Unio) forhesianus Lea, Syn., 1852, p. 24; 1870, p. 37. 



^\Unio moiissonianus Lea, Tr. Am. Phil. Soc, X, 1852, p. 268, pi. xviii, fig. 22; 



* Obs., V, 1852, p. 24, pi. xviii, fig. 22.— * Conrad, Pr. Acad. N. Sci. Phila., 

 VI, 1853, p. 252.— *H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 494.— 

 *B. H. Wright, Check List, 1888.— * P/ETel, Conch. Sam., Ill, 1890, p. 160. 



^ Margaron (Unio) moussonianiis Lea, Syn., 1852, p. 29; 1870, p. 46. 



' I am doubtful whether this is more than a small, rhomboid, southeastern variety 

 of crassidens, bearing the same relation to it that U. suigibbosus does to U. gibhosus. 



