NO. 1205. SYNOPSIS OF THE NJIADES— SIMPSON. 631 



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

 number of concentric ridges or corrugations, wbicli 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 papilla small ; anal opening smooth. 



fANODONTA CATARACTA Say.i 



Anodonta cataracta Say, Nich. Enc, 1st ed., II, 1816, pi. iii, fig. 4. — * Conrad, 

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

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

 Tr. Elem., I, 1853, Pt. 2, p. 218, pi. xxx, fig. 4.—^ Conrad, Pr. Ac. N, Sci. 

 Phila., VI, 1853, p. 263.—* Kuster, Conch. Cah. Ano., 1853, p. 33, pi. vii, fig, 

 2.— *P^TEL, Conch. Sam., Ill, 1890, p. 177.— *H. CARPENTKR,'Nautilus, IV, 

 1890, p. 56. 



*Unio calaracta Deshayes, Tr. Elem. Conch., 1839, p. 18, pi. xxx, fig. 1. 



^Anodoii cataracta Catlow and Reeve, Conch. Nom., 1845, p. 66. 



*Mytilus eataractus Eaton, Zool. Text-Book, 1826, p. 221. 



*Anodon eataractus Sowerby, Conch. Man., 1839, fig. 152; Conch. Icon., XVII, 

 1867, pi. IX, fig. 25. 



* ? Nytilus Jluriatilis Dillwyn, Cat., I, 1817, p. 316. — *Hanley, Ind. Test. Rev., 



1856, p. 69. 



* Anodonta fluviatilis 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.— *Latchford, Tr. Ot. F. N. Club, 1882, p. .56.—* B. H. 

 Wright, Check List, 1888. 



* Margarita {Anodonta) Jtuviatilis Lea, Syn., 1836, p. 51; 1838, p. 30. 



*Anodon fluviatilis Gould, Inv. Mass., 1841, p. 117, fig. 80.— *De Kay, Zool. of 



N. Y., Pt. 5, 1843, p. 203, pi. xviii, fig. 234.— * Catlow and Reeve, Conch. 



Nom., 1845, p. 66. — "Hartman and Michener, Conch. Cest, 1874, p. 94, fig. 



192.— Sowerby, Conch. Icon., XVII, 1869, pi. xxii, fig. 86.—* Binney, Inv. of 



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

 *Margaron (Anodonta) fluviatilis Lea, Syn., 1852, p. 50; 1870, p. 80. 

 *Mytilus marginatus Eaton, Zool. Text-Book, 1826, p. 224. 



* Anodonta dignota Ferussac, Guer. Mag., 1835, p. 25. 



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



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

 tig. 282.—* Clessin, Couch. Cab. Ano., 1874, p. 1.52, pi. XLix, figs. 1, 2.—* B. H. 

 . Wright, Check List, 1888.—* P^ tel, Conch. Sam., Ill, 1890, p. 186. 

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



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

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

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

 and I have never seen 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 J. 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. 



