SYNOPSIS OF THE XJ T. 1 1> ES S1MPSOX. 521 



Monog., vin, 1837, p. 66, pi. xxxvii, fig. 1. * HANLEY, Test. Moll., 1842, p. 



185; *Biv. Shells, 1843, p. 185.* CATLOW and REEVE, Conch. Nom., 1845, p. 



(>4. * KUSTKK, Conch. Cab. Unio, 1852, p. 62, pi. xiv, fig. 3. * CONRAD, Pr. 



Ac, X. Sci. Phila., VI, 1853, p. 257.* H. and A. ADAMS, Gen. Rec. Moll., II, 



1857, p.496. *REKVE, Conch. Icon., XVI, 1864, pi. xiv, fig. 58. *P,ETEL, 



Conch. Sam., Ill, 1890. p. 16S. 



*Ma>-tjarita ( Unio) soiccrbi/aniis LEA, Syn. 1836, p. 20; 1838, p. 17. 

 'Mari/aron (I'nio) xowerbi/aiuin I.K.V. Syn. 1852, p. 25; 1870, p. 38. 



Tennessee and Cumberland river systems. 



tTRUNCILLA OTHCALOOGENSIS Lea. 



I'nio othcaloogensia LEA, Proc. Acad. N. Sci. Phila., IX, 1857, p. 32 ;' Jl. Ac. N. Sci. 



1'hila., IV, 1858, p. 74, pi. xiv, fig. 54 ; Obs. VI, 1858, p. 75, pi. xiv, fig. 54. 

 ~ Mnrt/aron ( Unio) othcaloogensin LEA, Syn. 1870, p. 38. 



Otlicalooga Creek, Gordon County, Georgia. 



Subgenus DYSNOMIA Agassiz. 1852. 

 (Type, I'nio 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 ridge. Animal with mantle beauti- 

 fully maculate on its border; female animal unknown. 



tTRUNCILLA FOLIATA Hildreth. 



* Unio foliat us HILDRETH, Am. Jl. Sci., XIV, 1828, p. 284, fig. 16.* CONRAD, New 



F. W. Shells, 1834, p. 69. * FERCSSAC, Gner. Mag., 1835, p. 27. * HANLEY, 

 Test. Moll., 1842, p. 176; * Biv. Shells, 1843, p. 176. * CATLOW and REEVE, 

 Conch. Nom., 1845, p. 59. *H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 

 497.* CHENI-, Man., 1859, II, p. 143, fig. 705.* HARPER, L. and F. W. Shells 

 of Cinti., p. 4. 



*lfargarita ( Unio) foliat us LEA, Syn. 1836, p. 13; 1838, p. 14. 



*Maroaron ( Unio) foliaiux LKA, Syn. 1852, p. 20; 1870, p. 30. 



* I'nio .//eM'Ho.s/fs CONRAD, Monog. 1, 1835, p. 8, pi. iv, fig. 2. *KUSTER, Conch. Cab. 



Unio, 1852, pp. 46, 211, pi. ix, fig. 2; LXX, fig. 1. *CoNRA, Pr. Ac. N. 

 Sci. Phila., VI, 1853, p. 249. * REEVE, Conch. Icon., XVI, 1864, pi. vi, fig. 22; 

 xni, fig. 53. 

 *Dysnomia flexnosa AGASSIZ, Arch, fur Naturg. 1, 1852, p. 43. 



Ohio River drainage. 



tTRUNCILLA STEWARDSONI Lea. 



* I'nio steicardxoni LEA, Tr. Am. Phil. Soc., X, 1852, p. 278, pi. xxm, fig. 36; * Obs. 



V, 1852, p. 34, pi. xxm, fig. 36. * CONRAD, Pr. Acad. Nat. Sci. Phila., VI, 

 1853, p. 258. *H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 488. * REEVE, 

 Conch. Icon., XVI, 1864, pi. xv, fig. 66. *P^TEL, 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 buff-colored, shining shell, somewhat more elongated than T. haysiana, but 

 which probably groups wilh it. 



