590 PROCEEDINGS OF THE NATIONAL MUSE I'M. 



tMEDIONIDUS PARVULUS Lea. 



Hi 10 parrnlus LEA, Pr. Ac. N. Sci. Phila., IV, 1860, p. 307 ; " .11. Ac. N. Sci. Phila., 



VI, 1866, p. 45, pi. xvi, fig. 43; *Obs., XL, 1867, p. 49, pi. xvi, fig. 43.* B. H. 

 WRIGHT, Check List, 1888. 

 * Maryaron ( Unio) j>arruJun LEA, Syn.. 1870, p. 32. 



Ooosa River, Alabama; Chattanooga and Swamp creeks, northwest 

 Georgia. 



fMEDIONIDUS PENICILLATUS Lea. 



Unio penicillatus EA, Pr. Ac. N. Sci. Phila., IX, 1857, p. 171; *J1. Ac. N. Sci. 

 Phila., IV, 1859, p. 203, pi. xxm, fig. 85; *Obs., VII, 1859, p. 21, pi. xxm, 

 fig. 85. * B. H. WRIGHT, Check List, 1888. 



* Maryaron ( Unio) penlcillatus LEA, Syn., 1870, p. 32. 



Chattahoochee and Flint rivers, Georgia. 



tMEDIONIDUS KINGI B. H. Wright. 

 Unio kingi B. H. WRIGHT, Nautilus, XII, 1900, p. 138. 

 Branch of Flint River, Baker County, Georgia. 



tMEDIONIDUS ACUTISSIMUS Lea. 



- Unio aciitissimus LEA, Tr. Am. Phil. Soc., IV, 1831, p. 89, pi. x, fig. 18; *Obs., I, 



1834. p. 99, pi. \, tig. 18.* CONRAD, New F. W. Shells, 1834, p. 67. " FERUSSAC, 

 Guer. Mag., 1835, p. 28. * CONRAD, Monog., X, 1838, p. 86, pl.XLVii, fig.2. 



* HANLEY, Test. Moll., 1842, p. 177; *Biv. Shells, 1843, p. 177, pi. xxn, fig. 35. 

 *CATLOW and REEVE, Couch. Nom., 1845, p. 55. * CONRAD, Pr. Ac. N. Sci. 

 Phila., VI, 1853, p. 244.* H. and A. ADAMS. Gen. Kec. Moll., II, 1857, p. 497. 



* CHENU, 111. Conch., 1858, pi. vm, tigs. 3, 3o, 30. *SOWERBV, Couch. Icon., 

 XVI, 1866, pi. xxxvi, fig. 189. *B. H. WRIGHT, Check List, 1888. *P/ETEL, 

 Couch. Sam., III. J890, p. 143. 



*Maryarita ( Unio) acntissimm LEA, Syn., 1836, p. 14; 1838, p. 14. 

 *Maryaron ( Unio) actitlxsimm LEA, Syn., 1852, p. 21; 1870, p. 32. 

 *Unio semiplicatus K LISTER, Conch. Cab. Unio, 1862, p. 279, pi. xciv, tig. 4.' 

 *P,ETEL, Conch. Sam., Ill, 1890, p. 167. 



* Unio rubellinus LEA, Pr. Ac. N. Sci. Phila., IX, 1857, p. 32; * Jl. Ac. N. Sci. Phila., 



IV, 1858, p. 70, pi. xin, fig. 51; f Obs., VI, 1858, p. 70, pi. xin, lig. 51. 



* SOWKRBY, Conch. Icon., XVI, 1868, pi. xc, fig. 490. *B. H. WRIGHT, Check 

 List, 1888." P.ETEL, Conch. Sam., Ill, 1890, p. 166. 



*Maryaron ( Unio) rubeUinus LKA, Syn., 1870, p. 32. 



Alabama River system. 



(Group of Metlioniflus walkeri.) 



Shell rather short, inflated, with a high, posterior ridge; posterior 

 slope strongly corrugated; epidermis dark, slightly clouded; nacre red- 

 dish or greenish. 



l There is a Unio semipllcatiw of Troschel in Wiegman's Archiv. for 1841, p. 180. but 

 I do not kno\v what is. Knster credits his species to Australia, but it is evidently 

 Lea's shell, no such species being found in Australia. 



