NO. 1205. SYNOPSIS OF THE XJTADES— SIMPSON. 733 



developed posterior ridge; beaks full, their sculpture not observed; 

 epidermis smooth and shining in the young shell, becoming duller and 

 roughened when old; hinge moderately strong; pseudocardinals radial, 

 roughened ; laterals heavy, somewhat remote, curved ; there is a more 

 or less developed secondary lateral in the right valve ; dorsal scars few, 

 in a row just behind the pseudocardinals and fully exhibited on the 

 inner edge of the shallow beak cavity; nacre dull: muscle scars distinct, 

 smooth. 



Animal with the marsupium occupying the whole of the outer gills; 

 inner gills free from the abdominal sac a part of their length; palpi 

 rather small; mantle line thick on the border. 



tUNIO DOWNIEI Lea. 



^U7iiodownieiIjEA, Pr. Ac. Nat. Sci. Phila., II, 1858, p. 166; Jl. Ac. Nat. Sci. Phila., 



IV, 1859, p. 210, pi. XXV, fig. 91; Obs., VII, 1859, p. 28, pi. xxv, fig. 91.— 



*SowERBY, Conch. Icou., XVI, 1868, pi. lxviii, fig. 350. — * B. H. Wright, 



Check List, 1888.— * P^tel, Conch. Sam., Ill, 1890, p.l51.—* Simpson, Pr. 



, '• U. S. Nat. Mus., XV, 1892, p. 413, pi. lv, figs. 1-3; lvi, fig. 5. 



^ Mar gar on (Unto) dotvniei Lea, Syn., 1870, p. 41. 



Southern Georgia; north Florida. 



tUNIO GEMINUS Lea. 



* Unio geminus Lea, Pr. Ac. Nat. Sci. Phila., VIII, 1856, p.- 262; * Jl. Ac. Nat. Sci. 



Phila., 1858, p. 63, pi. X, fig. 45; "^ Obs., VI, 1858, p. 63, pi. x, fig. 45.—^ B. H. 

 W^KiGHT, Check List, 1888. 

 ^ Mar gar on (Unio) geminus Lea, Syn., 1870, p. 41. 



* t Unio satillaensis Lea, Pr. Ac. Nat. Sci. Phila., II, 1858, p. 166; * Jl. Ac. Nat. Sci. 



Phila., IV, 1859, p. 216, pi. xxvii, fig. 96; Obs., VII, 1859, p. 34, pl.xxvii, 

 fig. 96.—* B. H. Wright, Check List, 1888. 

 ^Mttrgaron {Unio) satillaensis Lea, Syn., 1870, p. 41. 



Georgia. 



fUNIO LECONTIANUS Lea. 



^Margarita (Unio) lecontianiis Lea, Syn., 1836, p. 23; 1838, p. 18. 



*Unio lecontianus Lea, Tr. Am. Phil. Soc, VI, 1838, p. 40, jjl. xii, fig. 35; * Obs., 

 II, 1838, fig. 40, pi. XII, fig. 35.— * Troschel, Arch. fiirNaturg., V, 1839, Pt.2, 

 p. 236.— ** HANI.EY, Test. Moll., 1842, p. 188; '^Biv. Shells, 1843, p. 188, pi. 

 XXII, figs. 11,51. — "" Catlow and Reeve, Conch. Nom., 1845, p. 60. — * Conrad, 

 Pr. Ac. Nat. Sci. Phila., VI, 1853, p. 251.— *Chenu, 111. Conch., 1858, pi. 

 XXIV, figs. 6, 6a, 6&. — *H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 494. — 

 "SowERBY, Conch. Icon., XVI, 1866, pl.x^^xui, fig. 173.— * B. H.Wright, 

 Check List, 1888.— *P.etel, Conch. Sam., Ill, 1890, p. 157. 



^Margaron ( Unio) lecontianus Lea, Syn., 1852, p. 26; 1870, p. 41. 



""Unio contrarius Conrad, Pr. Ac. Nat. Sci. Phila., IV, 1849, p. 153; *Aun. and 

 Mag., IV, 1849, p. 301 ; * Jl. Ac. Nat. Sci. Phila., 1850, p. 276, pi. xxxvii, fig. 7; 

 * Pr. Ac. N. Sci. Phila., VI, 1853, p. 247. 



Georgia. 



