SYNOPSIS OF THE XAIADES—SIMPSON. 551 



p. 271, pi. XX, tig. 27 ; * Obs., V, 1852,.p. 27, pi. xx, tig. 27.— *Conrad, Pr. Ac. N. 



Sci. Phila., VI, 1853, p. 255.— *H. and A. Adams, Gen. Eeo. Moll., II, 1857, p. 



494.— *B. H.Wright, Check List, 1888.— P^tel, Conch. Sam., Ill, 1890, p. 



164. 

 *Margaron ( Unio) proximm Lea, Syn., 1852, p. 29; 1870, p. 45. 

 Unio tenerus Simpson, Pr, U. S. Nat. Mus., XV, 1892, p. 416, pi. lviii, figs. 5 and 8.' 



Neuse River, Kortli Caroliua; south to nortli Florida; west to the 

 Etowah Elver, Georgia; Duck Eiver, Tennessee. 



t LAMPSILIS CONSTRICTUS Conrad. 



* Unio Uenosus var. constrictus Conrad, Monog. X, 1838, p. 91, pi. XLix, fig. 4. 

 *Unio constrictus Conrad, Pr. Ac. N. Sci. Phila., VI, 1853, p. 247. — "H. and A. 



AdaxMS, Gen. Rec. Moll. II, 1857, p. 493.— *Sowerby, Conch. Icon., XVI, 1868, 

 pi. Lxxxvii, fig. 464.— "B. H. Wright, Check List, 1888.— ^P^etel, Conch. 

 Sam., Ill, 1890, p. 148. 

 * Margaron ( Unio) constrictus Lea, Syn., 1852, p. 29 ; 1870, p. 46. 



* Unto genthii Lea, Pr. Ac. N. Sci. Phila., 1, 1857, p. 85; "Jl. Ac. N. .Sci. Phila., 1862, 



p. 57, pi. II, fig. 204; *Obs. VIII, 1862, p. 61, pi. ii, fig. 204.— *B. H. Wright, 

 Check List, 1888.— *Pjetel, Conch. Sam., Ill, 1890, p. 153. 

 ^Margaron ( Unio) genthii Lea, Syn., 1870, p. 41. 



James River, Virginia; south to South Carolina; Floyd County, 

 northwest Georgia; northern Alabama; Tennessee. 



t LAMPSILIS APICINUS Lea. 



* Unio cqncinus Lea, Pr. Ac. N. Sci. Phila., IX, 1857, p. 32 ; ''Jl. Ac. N. Sci. Phila., 



IV, 1858, p. 76, pi. XIV, fig. 56; *Ohs., VI, 1858, p. 76, pi. xiv, fig. 56.— *B. H. 

 Wright, Check List, 1888. 



* Margaron ( Unio) apicinus Lea, Syn., 1870, p. 44. 



Othcalooga Creek, Gordon County, Georgia. 



t LAMPSILIS OCCIDENTALIS Conrad. 



* Unto occidentalis Conrad, Monog., VII, 1836, p. 64, pi. xxxvi, fig. 1; ""Pr. Ac. N. 



Sci. Phila., VI, 1853, p. 253.— "H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 

 492.— *B. H. Wright, Check List, 1888.— ^Pj^tel, Conch. Sam., Ill, 1890, 

 p. 161. 



* Margaron ( Unio) occidentalis Lea, Syn., 1852, p. 33; 1870, p. 53. 



Current and Little Red rivers, Arkansas. 



t LAMPSILIS NIGERRIMUS Lea. 



* Unio nigerrimus Lea, Tr. Am. Phil. Soc, X, 1852, p. 268, pi. xviii, fig. 23; *0b8.,V, 



1852, p. 24, pi. XVIII, fig. 23.— *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^tel, Conch. Sam., Ill, 1890, p. 161. 



* Margaron ( Unio) nigerrimns Lea, Syn., 1852, p. 31; 1870, p. 49. 

 'UniofuHgo Reeve, Conch. Icon., XVI, 1856, pi. xxx, tig. 159.— *P^tel, Conch. 



Sam., Ill, 1890, p. 153. 



Alexandria, Louisiana, to eastern Texas; Indiana"? 



{Group of Lmnpsilis iris.) 



Shell rather small, elliptical, moderately solid in front, thinner 

 behind; epidermis covered with dark green, broken rays, beak sculp- 



^ As of Ravenel, who, however, never described the species. 



