NO. 1205. SYNOPSIS OF THE NAIADES SIMPSON. 631 



dorsal region ; beaks rather full, the sculpture consisting of a moderate 

 number of concentric ridges or corrugations, which are generally some- 

 what doubly looped, and often slightly nodulous; epidermis bright and 

 shining, sometimes faintly rayed. 



Animal with large branchiae, the inner larger in front, free in part 

 from the abdominal sac; marsupium occupying the entire outer gills, 

 forming an enormously thick, liver-colored pad when filled; mantle thin, 

 thickened on its edge; branchial papill.e small; anal opening smooth. 



tANODONTA CATARACTA Say.' 



Anodonta caiaracta SAY, Nich. Enc., Isted., II, 1816, pi. in, fig. 4. * CONRAD, 



New L. and F. W. Shells, 1834, p. 73. * FERUSSAC, Guer. Mag., 1835, p. 25. 



* DKSIIAYES, An. sans Vert., 2d ed., VI, 1835, p. 566; 3d ed., II, 1839, p. 678; 



Tr. Elern., I, 1853, Pt. 2, p. 218, pi. xxx, fig. 4.* CONRAD, Pr. Ac. N. Sci. 



Phila., VI, 1853, p. 263. "KusTER, Conch. Cab. Auo.,1853, p. 33, pi. vn, tig. 



2. *PyETEL, Conch. Saui., Ill, 1890, p. 177. *H. CARPENTER, Nautilus, IV, 



1890, p. 56. 



I'nio caiaracta DESIIAYES, Tr. Eleni. Conch., 1839, p. 18, pi. xxx, fig. 1. 

 *Anodon cataracta CATLOW aud REEVE, Conch. Noni., 1845, p. 66. " 

 *Mytilu8 cataractus EATON, Zool. Text-Book, 1826, p. 221. 

 *Anodo cataractus SOWERBY, Conch. Man., 1839, fig. 152; Conch. Icon., XVII, 



1867, pi. ix, fig. 25. 



* ? MytiluxJlHviatilis DILLWYN, Cat., I, 1817, p. 316. *HANLEY, Ind. Test. Rev., 



1856, p. 69. 

 * Anodonta Jiitviatilis Bosc, Hist. Nat. Coq., 1824, III, p. 143. * HANLEY, Test. 



Moll., 1842, p. 217. *C. B. ADAMS, Thompson's Hist, of Vt., 1842, p. 164; 



^F. W.and L. S. of Vt., 1842, p. 14. * HANLEY, Biv. Shells, 1843, p. 217. 



*STIMPSON, Shells of N. Eng., 1851, p. 15. *H. and A. ADAMS, Gen. Rec. 



Moll., II, 1857, p. 502. *LATCIIFORD, Tr. Ot. F. N. Club, 1882, p. 56. *B. H. 



WRIGHT, Check List, 1888. 



"Margarita (Anodonta) Jiuviatilis LEA, Syn., 1836, p. 51; 1838, p. 30. 

 *Anodon fluvialilis GOULD, Inv. Mass., 1841, p. 117, fig. 80. *DE KAY, Zool, of 



N. Y., Pt. 5, 1843, p. 203, pi. xvm, fig. 234. * CATLOW and REEVE, Couch. 



Noni., 1845, p. 66. * HAKTMAX and MICHENER, Couch. Cest, 1874, p. 94, fig. 



192. SOWERBY, Couch. Icon., XVII, 1869, pl.xxn, fig. 86. * BINNEY, Inv. of 



Mass., 2d ed., 1870, p. 178, fig. 480. 



*Margaron ( Anodonta) fluviatil is LEA, Syn., 1852, p. 50; 1870, p. 80. 

 *Mytilit8 margin atus EATON, Zool. Text-Book, 1826, p. 224. 



* Anodonta ditjnota FERUSSAC, Guer. Mag., 1835, p. 25. 



* t Anodonta rirgulata LEA, 2 Pr. Ac. N. Sci. Phila,, I, 1857, p. 86; .11. Ac. N. Sci. 



Phila., V, 1862, p. 213, pi. xxxii, fig. 282; *Obs., IX, 1863, p. 35, pi. xxxin, 

 fig. 282.* CLESSIN, Conch. Cab. Ano., 1874, p. 152, pi. XLIX, figs. 1. 2.* B. H. 

 WRIGHT, Check List, 1888.* P^ETEL, Conch. Sam., Ill, 1890, p. 186. 

 *Margaron (Anodonta) virgulata LEA, Syn., 1870, p. 80. 



1 This species is probably better known by Dillwyn's name, fluvialilis. According 

 to Lea and Binney, the first edition of Nicholson's Encyclopedia appeared in 1816, 

 which would give Say's name priority by one year. This edition is extremely rare, 

 and I have never seeu it. It is claimed by some authors to have been issued in 1817. 

 Dillwyn refers his species to Gmelin, who states that his shell came from the fresh 

 waters of Europe, and is allied to anatina, and it is quite likely it is A. cygnea. As 

 there can be no doubt about Say's species, I think it best to use his name. 



2 1 think this is merely a southern form of cataracta and scarcely worthy of a 

 varietal name. 



