NO. 1205. 



SYNOPSIS OF THE NAIADES— SIMPSON. 635 



with 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 imhecillis Say, N. Harm. Diss., II, No. 23, 1829, p. 355. — * Conrad, New 

 F. W. Shells, 1834, p. 73.—* Ferussac, Guer. Mag., 1835, p. 25.'-* L. Say, Terr, 

 and Fluv. Shells, 1840, p. 13.— * Conrad, Pr. Ac. N. Sci. Phila., VI, 1853, p. 

 264.— *H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 502.— * Calkins, Pr. 

 Dav. Ac. Sci., 1874, p. 47.—* Clkssin, Conch. Cab. Ano., 1874, p. 70, pi. xlix, 

 figs. 4, 5; XXV, tig. 4.—* B. H. Wright, Check List, 1888.— * P/ETel, Conch. 

 Sara., 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. 



* Margaron {Anodonta) imhecillis Lea, Syn., 1852, p. 50; 1870, p. 80. 

 *Anodon imbecillis Sowerby, Conch. Icon., XVII, 1870, pi. xxvii, fig. 102. 



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



1834, p. 158, pi. VI, fig. 16.—* Ferussac, Gner. Mag., 1835, p. 25. — * Hanley, 

 Test. Moll., 1842, p. 218.—* P^tel, Conch. Sam., Ill, 1890, p. 180. 



* Margarita (Anodonta) incerta Lea, Syn., 1836, p. 51; 1838, p. 30. 

 * Anodon incerta Catlow and Reeve, Conch. Nom., 1845, p. 67. 

 *Anodon incertus Sowerby, Couch. Icon., XVII, 1867, pi. xvii, fig. 59. 

 "Anodon liorda Gould, Pr. Bost. Soc. N. H., V, 1855, p. 229; * Otia Conch., 1862, 



p. 218. 



* Anodonta hordeum P^tel, Conch. Sam., Ill, 1890, p. 180. 



Entire Mississippi drainage area; south Michigan; North Carolina 

 to Georgia; southwest to Matamoras, Mexico. 



tANODONTA HENRYANA Lea.' 



"'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^tel, Conch. Sam., Ill, 1890, p. 180.— 



* Fischer and Crosse, Miss. Sci., Pt. 7, II, 1894, p. 525. 



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



* Anodon henryana Sowerby, Conch. Icon,, XVII, 1870, pi. xxxiv, fig. 140.^ 



Northeast Mexico; southern Texas. 



tANODONTA GIBBOSA Say.' 



Anodonta glbbosa Say, Exp. to St. Peters R., 1824, p. 265, pi. xiv, figs. 3, 4. — 



* Ferussac, 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. xviii, fig. 3.—* B. H, Wright, Check List, 

 1888.— *P^tel, Conch. Sam., Ill, 1890, p. 179. 



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

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

 it is probably only a variety of the latter. 



^Anodonta impura Say, (Disseminator, 1829, p. 355) from Mexico has never been 

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

 henryana. 



•■'An exceedingly variable species in form, size, and solidity. A. dunlapiana seems 

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



