742 PEOCEEBINGS OF THE NATIONAL MUSEUM. vouxxii. 



* Unio declivis Coa^rad, Monog., V, 1836, p. 45, pi. xxiii, fig. 1. 



* t Unio ineptus Lea, Tr. Am. Phil. Soc, X, 1852, p. 261, pi. xv, fig. 12; * Obs., V, 



1S52, p. 17, pi. XV, fig. 12.— * Conrad, Pr. Acad. N. Sci. Phila., VI, 1853, p. 

 250.—* H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 494.—* B. H. Wright, 

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



* Margaron ( Unio) ineptus Lea, Syn., 1852, p. 31; 1870, p. 50. 



* t Unio hebes Lea, Tr. Am. Phil. Soc, X, 1852, p. 267, pi. xviii, fig. 21 ; * Obs., V, 



1852, p. 23, pi. XVIII, fig. 2L—* Conrad, Pr. Ac. N. Sci. Phila., VI, 1853, p. 

 250.— *H. and A. Adams, Gen. Rec. Moll., II, 1857, p.494.— *B. H. Wright, 

 Check List, 1888.— *• P^tel, Conch. Sam., Ill, 1890, p. 154. 



* Margaron ( Unio) hebes Lea, Syn., 1852, p. 26; 1870, p. 51. 



*\Unio rivularis Conrad, Pr. Ac. N. Sci. Phila., VI, 1853, p. 257.— * Conrad, Jl. 



Ac. N. Sci. Phila., 1854, p. 296. 

 *\Unio cicur Lea, Pr. Ac. N. Sci. Phila., V, 1861, p. 39; *J1. Ac. N. Sci. Phila., 



V, 1862, p. 93, pi. XIII, fig. 241.— * Obs., VIII, 1862, p. 96, pi. xiii, fig. 241.— 

 B. H. Wright, Check List, 1888. 



* Margaron ( Unio) cicur Lea, Syn., 1870, p. 52. 



* Unio squalidus Lea, (part) ^ Pr. Ac. N. Sci. Phila., XV, 1863, p. 192.— *J1. Ac. N. 



Sci. Phila., VI, 1866, p. 22, pi. vii, fig. 20; * Obs., XI, 1867, p. 26, pi. vii, fig. 

 20.—* B. H. Wright, Check List, 1888. 



* Margaron ( Unio) squalidus Lea, Syn., 1870, p. 51. 



* t Unio jeivettii Lea, Pr. Ac. N. Sci. Phila., XI, 1867, p. 81 ; * Jl. Ac. N. Sci. Phila., 



VI, 1868, p. 276, pi. xxxvii, fig. 89 ; *Obs., XII, 1869, p. 36, pi. xxvii, fig. 89.— 



* B. H. Wright, Check List, 1888. 



* Margaron ( Unio) jeivettii Lea, Syn., 1870, p. 51. 



*iUnio2yaive7isis Lea,^ Pr. Ac. N. Sci. Phila., XII, 1868, p. 161; * Jl. Ac. N. Sci 

 Phila., VI, 1868,p. 302, pi. xlv, fig. 114; * Obs., XII, 1869, p. 62, pL XLV, fig. 

 114.—* B. H. Wright, Check List, 1888. 



^Margaron (Unio) paivensis Lea, Syn., 1870, p. 51. 



*iUnio rivicolus Conrad, Am. Jl. Conch., IV, 1868, p. 280, pi. xviii, fig. 4.— 



* B. H. Wright, Check List, 1888. 



*tUNIO OBESUS var. BLANDINGIANUS Lea. 



■Unio blandingianus Lea, Tr. Am. Phil. Soc, V, 1834, p. 101, pi. xv, fig. 44 ;3 

 *.Obs., I, 1834, p. 213, pi. xv, fig. 44,—* Ferussac, Guer. Mag., 1835, p. 29.— 



* Conrad, Monog., V, 1836, p. 46. pi. xxiii, fig. 2.—* Hanley, Test. Moll., 1842, 

 p. 200 ; * Biv. Shells, 1843, p. 200, pi, xxii, fig. 1.—* Catlow and Reeve, Conch. 

 Norn., 1845, p. 56.—* Kuster, Conch. Cab. Unio, 1852, p. 36, pi. vi, fig. 2.— 



* Conrad, Pr. Ac. Nat. Sci. Phila., VI, 1853, p. 245.—* H. and A. Adams, Gen. 

 Rec. Moll., II, 1857, p. 492.—* Sowerby, Conch. Icon., XVI, 1866, pi. xxxv, 

 fig. 187.—* B. H. Wright, Check List, 1888.—* S. H. Wright, Conch. Ex., II, 

 1888, p. 95.—* Fjetki., Conch. Sam., Ill, 1890, p. 146, 



* Margarita ( Unio) blandingianus Lea, Syn., 1836, p, 32; 1838, p. 22, 

 ^Margaron (Unio) blandingianus Lea, Syn,, 1852, p, 33; 1870, p, 54. 



1 Under this name Dr. Lea has certainly described two species, a heavy quadrate, 

 form biangulate behind, with jinrple nacre — a variety of complanatus — and another 

 which is, no doubt, U. obesus, and is the shell figured. 



'-A rough, apparently diseased obesus. 



^A. decidedly trapezoidal form with cloth-like, dark epidermis, possibly worthj of 

 a varietal name. The transition to the typical state is, however, very complete. 



