NO. 1205. SYNOPSIS OF THE NATJDES— SIMPSON. 521 



Monog., VIII, 1837, p. 66, pi. xxxvii, fig. 1.— ^Hanley, Test. Moll., 1842, p. 



185; ""Biv. Shells, 1843, p. 185.—* Catlow and Eeeve, Conch. Nom., 1845, p. 



64. — * KuSTER, Conch. Cab. Unio, 1852, p. 62, pi. xiv, lig, 3. — * Conrad, Pr. 



Ac. N. Sci. Phila., VI, 1853, p. 257.—'' H. and A. Adams, Gen. Eec. Moll., II, 



1857, p. 496.—* Eeeve, Conch. Icon., XVI, 1864, pi. xiv, fig. 58.— '^ P^etel, 



Couch. Sam., Ill, 1890, p. 168. 

 ^Margarita (Unio) soicerhijanus Lea, Syn. 1836, p. 20; 1838, p. 17. 

 ^Margaron ( Unio) sowerhyaniis Lea, Syn. 1852, p. 25; 1870, p. 38. 



Tennessee and Cumberlaud river sj^stems. 



tTRUNCILLA OTHCALOOGENSIS Lea. 



-■ I'liio oikccdoogensis Lea, Proc. Acad. N. Sci. Phila., IX, 1857, p. 32; i Jl. Ac. N. Sci. 



Phila., IV, 1858, p. 74, pi. xiv, lig. 54 ; Obs. VI, 1858, p. 75, pi, xiv, fig. 54. 

 ■ ilargaron (Unio) ofJicaloogensis Lea, Syn. 1870, p. 38. 



Othcalooga Greek, Gordon County, Georgia. 



Subgenus DYSNOMIA Agassiz. 1852. 



(Ty])e, Unio foliattis Hildreth.) 



Shell of the male with a posterior and central radiating- ridge, with 

 a wide, flattened space between; that of the female with a greatly pro- 

 duced inflation, which is but little behind the center of the base, it 

 being a continuation of the central ridg'e. Animal with mantle beauti- 

 fully maculate on its border; female animal unknown. 



tTRUNCILLA FOLIATA Hildreth. 



^Uniofoliatus Hildreth, Am. Jl. Sci., XIV, 1828, p. 284, fig. 16. — * Conrad, New 

 F. W. Shells, 1834, p. 69.— * Ferussac, Guer. Mag., 1835, p. 27. — *Hanley, 

 Test. Moll., 1842, p. 176; *Biv. Shells, 1843, p. 176.— * Catlow and Eeeve, 

 Conch. Noiii., 1845, p. 59. — *H. and A. Adams, Gen. Eec. Moll., II, 1857, p. 

 497.—* Chenu, Man., 1859, II, p. 143, fig. 705.—* Harper, L. and F. W. Shells 

 of Cinti., p. 4. 



*Margariia ( Unio) foUuliis Lea, Syn. 1836, p. 13; 1838, p. 14. 



*Margaron ( Unio) foliatiis Lea, Syn. 1852, p. 20 ; 1870, p. 30. 



* Unio flexnosHS Coxkad, Monog. 1, 1835, p. 8, pi. iv, fig. 2. — * Kuster, Conch. Cab. 



Unio, 1852, pp. 46, 211, pi. ix, fig. 2; Lxx, fig. 1.—* Conrad, Pr. Ac. N. 

 Sci. Phila., VI, 1853, p. 249.—* Eeeve, Couch. Icon., XVI, 1864, pi. Y\, fig. 22; 

 xiii, fig. 53. 

 *Dysnomia flextiosa Agassiz, Arch, flir Naturg. 1, 1852, p. 43. 



■ Ohio Kiver drainage. 



tTRUNCILLA STEWARDSONI Lea. 



* Unio steu-ardsoni Lea, Tr. Am. Phil. Soc, X, 1852, p. 278, pi. xxiii, fig. 36; * Obs. 



V, 1852, p. 34, pi. XXIII, fig. 36.— * Conrad, Pr. Acad. Nat. Sci. Phila., VI, 

 1853, p. 258.— *H. and A. Adams, Gen. Eec. Moll., II, 1857, p. 498. — * Eeeve, 

 Conch. Icon., XVI, 1864, pi. xv, fig. 66.— *Pj2Tel, Conch. Sam., Ill, 1890, 

 p. 168. 

 ^Margaron (Unio) stewardsoni Lea, Syn. 1852, p. 20; 1870, p. 38. 



Tennessee Eiver. 



1 1 have seen only the type of this species, apparently a young female, which is a 

 reddish buif-colored, shining shell, somewhat more elongated thau T. haysiana, but 

 which probably groups with it. 



