554 PROCEEDINGS OF THE NATIONAL MUSEUM. 



Sci. Phila., VI, 1853, p. 247. *H. and A. ADAMS, Gen. Rec. Moll., II, 1857, 

 p. 493. * CIIKNU, 111. Conch., 1858, pi. xxiv, figs. 1, la, 15. * SOWERBY, 

 Conch. Icon., XVI, 1866, pi. xxxvi, fig. 197.* B. H. WRIGHT, Check List, 

 1888.* P.ETEL, Couch. Sam., Ill, 1890, p. 149. 



* Margaron ( Unio) cumberlandicus LEA, Syn., 1870, p. 48. 



t * Un'w notatus LEA,Tr. Am. Phil. Soc.,VI, 1838, p. 28, pl.vm, fig.22 ; * Obs., II, 1838, 

 p. 28, pi. vni, fig. 22. *TROSCHEL, Arch, fur Nat., V, 1839, Pt. 2, p. 235. 



* HANLEY, Test. Moll., 1842, p. 193 ; * Biv. Shells, 1843, p. 193, pi. xxm, fig. 9. 



* CATLOW and REEVE, Conch. Nona., 1845, p. 61. * H. and A. ADAMS, Gen. Rec. 

 Moll., II, 1857, p. 494. *CHENU, 111. Conch., 1858, pi. xxi, figs. 3, 3a, 3b. 



* B. H. WRIGHT, Check List, 1888.* P.ETEL, Conch. Sam., Ill, 1890, p. 161. 



* Margarita ( Unio) notatua LEA, Syn., 1836, p. 26; 1838, p. 19. 



* Manjaron ( Unio) notatus LEA, Syn., 1852, p. 29; 1870, p. 45. 



t* Unio glaber LEA, Tr. Am. Phil. Soc., VI, 1838, p. 34, pi. X, fig. 29; *Obs., II, 

 1838, p. 34, pi. x, fig. 29.* TROSCHEL, Arch. fur. Naturg., V, 1839, Pt. 2, p. 

 236.^ HANLEY, Test. Moll., 1842, p. 196; *Biv. Moll., 1843, p. 196, pi. xxm, 

 fig. 2. * CATLOW and REEVE, Conch. Norn., 1845, p. 59. * CONRAD, Pr. Ac. 

 X. Sci., Phila., VI, 1853, p. 250.* H. and A. ADAMS, Gen. Rec. Moll., II, 1857, 

 p. 494. *CHENU, 111. Conch., 1858, pi. xxiv, figs. 3, 3a, 36. * SOWERBY, 

 Conch. Icon., XVI, 1868, pi. LXXXV, fig. 452.* B. H. WRIGHT, Check List, 

 1888. *PJTEL, Conch. Sam., 111,1890, p. 153. 



* Margarita ( Unio) glaber LEA, Syu., 1836, p. 28; 1838, p. 20. 



* Margaron ( Unio) glaber LEA, Syn., 1852, p. 31 ; 1870, p. 48. 



Twio radians LEA, Pr. Ac. N. Sci. Phila., IX, 1857, p. 32; * Jl. Ac. N. Sci. Phila., 

 IV, 1859, p. 201, pi. xxm, fig. 84; *Obs., VII, 1859, p. 19, pi. xxm, fig. 84. 

 B. H. WKIGHT, Check List, 1888. 



* Margaron (Unio) radians LEA, Syn., 1870, p. 46. 



t* I'liiojonesii LEA, Pr. Ac. N. Sci. Phila., Ill, 1859, p. 171; * Jl. Ac. N. Sci. Phila., 

 IV, 1860, p. 339, pi. LIV, fig. 164; *Obs., VIII, 1860, p. 21, pi. LIV, tig. 164. 



* B. H. WRIGHT, Check List, 1888. *P.ETEL, Conch., Sam., Ill, 1890, p. 156. 



* Margaron ( Unio) jonesii LEA, Syn., 1870, p. 48. 



t rnio discrepans LEA, Pr. Ac. N. Sci. Phila., IV, 1860, p. 92; * Jl. Ac. X. Sci. 



Phila., IV, 1860,p. 340, pi. LV, fig. 165; * Obs., VIII, 1860, p. 22, pi. LV, fig. 



165. * SOWERBY, Conch. Icon., XVI, 1866, pi. xxxiv, fig. 176. *B. H. 



WRIGHT, Check List, 1888.* P.ETEL, Conch. Sam., Ill, 1890, p. 151. 

 'Margaron ( Unio) discrepans LEA, Syn., 1870, p. 48. 

 t * Unio scitulus LEA, Pr. Ac. N. Sci. Phila., IV, 1860, p. 93; * Jl. Ac. N. Sci. Phila., 



IV, 1860, p. 342, pi. LV, fig. 167; * Obs., VIII, 1860, p. 24, pi. LV, fig. 167.* B. 



H. WRIGHT, Check List, 1888. 



* Margaron ( Unio) scitulus LEA, Syn., 1870, p. 45. 



t * Unio linguffiformis LEA, Pr. Ac. N. Sci. Phila., IV, 1860, p. 305; * Jl. Ac. N. Sci. 

 Phila., IV, 1860, p. 345, pi. LVI, fig. 170; * Obs., VIII, 1860, p. 27, pi. LVI, 

 fig. 170.* B. H. WRIGHT, Check List, 1888. 



* Margaron ( Unio) lingucpformis LEA, Syn., 1870, p. 48. 



t * Unio perpictus LKA, Pr. Ac. N. Sci. Phila., IV, 1860, p. 306; * Jl. Ac. N. Sci. 

 Phila., IV, 1860, p. 350, pi. LVIII, fig. 175; *Obs., VIII, 1860, p. 32, p]. 

 LVIII, fig. 175; *B. H. WRIGHT, Check List, 1888. 



* Margaron ( Unio) perpictus LEA, Syn., 1870, p. 44. 



t*7nio difficilis LEA,' Pr. Ac. N. Sci. Phila., XII, 1868, p. 144; * Jl. Ac. X. Sci. 



Phila., VI, 1869, p. 311, pi. XLIX, fig. 124; *Obs., XII, 1869, p. 71, pi. XLIX, 



fig. 124.* B. H. WRIGHT, Check List, 1888. 

 * Margaron (Unio) difficilis LEA, Syn., 1870, p. 46. 



1 Two shells are in the Lea collection ; one adult and badly worn, the other young, 

 I believe it to be only a form of nebulosus. 



