NO. 1205. sYxnrxrs or THI: x M.iDES-snirsox. fi35 



\\ itli beautiful, delicate, capillary rays; nacre bluish. Animal some- 

 times highly colored; gills nearly alike in size, often having a distinct 

 border of different texture; eye spots on branchial opening generally 

 perceptible. 



tANODONTA IMBECILLIS Say. 



Anodonta imbecillis SAY, N. Harm. Diss., II, No. 23, 1829, p. 1555. 'CONRAD, New 

 F. W. Shells, 1834, p. 73.* FKRUSSAC, Guer. Mag., 1835, p. 25. " L. SAY, Terr. 

 andFluv. Shells, 1840, p. 13. * CONRAD, Pr. Ac. N.^Sci. Phila., VI, 1853, p. 

 264. II. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 502. * CALKINS, Pr. 

 Dav. Ac. Sci., 1874, p. 47. * CLESSIN, Conch. Cab. Ano., 1874, p. 70, pi. XLIX, 

 figs. 4,5; xxv, fig. 4. * B. H. WRIGHT, Check List, 1888. * P.KTKL, Conch. 

 Sain., Ill, 1890, p. 180.* STEARNS, Pr. U. S. Nat. Mus., XIV, 1891, p. 106. 



* BAKER, Moll. Chicago, Pt. 1, 1898, p. 55. pi. v, fig. 1. 

 MarynroH (Anodonta} imbecillis LEA, Syn., 1852, p. 50; 1870, p. 80. 



' .1 notion imbecillis SOWERUY, Conch. Icon., XVII, 1870, pi. xxvu, fig. 102. 



* t Anodonta incerta LKA, Tr. Am. Phil. Soc., V, 1834, p. 46, pi. vi, fig. 16; * Obs., I, 



1834, p. 158, pi. vi, fig. 16.* FERUSSAC, Guer. Mag., 1835, p. 25.* HAM.KV, 

 Test. Moll., 1842, p. 218.* PASTEL, Conch. Sam., Ill, 1890. p. 180. 



* Margarita (Anodontu) hn-crta LEA, Syn., 1836, p. 51; 1838. p. 30. 

 *Anodon incerta CATLOW and KKEVE, Conch. Nom., 1845, p. 67. 

 ^Anodon incertns SOWERBY, Couch. Icon., XVII, 1867, pi. xvn, fig. 59. 

 *Anodon horda GOULD, Pr. Bost. Soc. N. H., V, 1855, p. 229; * Otia Conch., 1862, 



p. 218. 



* Anodonta hordeinn P.-KTEL, Conch. Sam., Ill, 1890, p. 180. 



Entire Mississippi drainage area; south Michigan; North Carolina 

 to (leorgia; southwest to Matamoras, Mexico. 



tANODONTA HENRYANA Lea. 1 



^Anodonta henryana LEA, Pr. Ac. N. Sci. Phila., I, 1857, p. 102; * Jl. Ac. N. Sci. 

 Phila., IV, 1860, p. 373, pi. LXVI, fig. 198; * Obs., VIII, 1860, p. 55, pi. LXVI, fig. 

 198. * CLESSIN, Conch. Cab. Ano., 1874, p. 141, pi. XLV, figs. 5. 6. * B. H. 

 WRIGHT, Check List, 1888. * P.KTEL, Conch. Sam. r III, 1890, p. 180. 



* FISCHER andCROSSE, Miss. Sci., Pt. 7, II, 1894, p. 525. 

 *Margaron (Anodonta) henryana LEA, Syn., 1870, p. 81. 



*Anodon henryana SOWERBY, Conch. Icon., XVII, 1870, pl.xxxiv, fig. 140. 2 



Northeast Mexico; southern Texas. 



tANODONTA GIBBOSA Say.' 



Anodonta y'Jtbosa SAY, Exp. to St. Peters R., 1824, p. 265, pi. xiv, figs. 3, 4. 



* FERTSSAC, Guer. Mag., 1835, p. 25; * CONRAD, Pr. Ac. N. Sci. Phila., VI, 1853, 

 p. 264.* H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 502.* CLESSIN, 

 Conch. Cab. Ano., 1873, p. 74, pi. xvm, fig. 3. * B. H. WRIGHT, Check List, 

 1888. *P.KTEL, Conch. Sam., Ill, 1890, p. 179. 



'Typically very distinct from imbecillis, having the dorsal aud basal lines quite 

 straight. But there are many intermediate forms which are very hard to place, aud 

 it is probably only a variety of the latter. 



~ 2 Anodonta impnra Say, (Disseminator, 1829, p. 355) from Mexico has never been 

 figured and was only briefly described. It is quite likely that it is the same as A. 

 henryana. 



3 An exceedingly variable species in form, size, and solidity. ./. dunlapiana seems 

 to me to be only a slightly elongated, rather solid form. 



