SYNOPSIS OF THE NA I. iDES— SIMPSON. 507 



frequently imperfect or nearly wanting ; laterals remote ; anterior mnscle 

 scars often complicated; dorsal scars consisting- of a row of from four 

 to thirty distinct, often deep impressions, running from the cavity of 

 the beak obliquely downward anteriorly; nacre purplish. Animal 

 \vith large branchi*; marsupium consisting of numerous, generally 

 fine ovisacs, which are often somewhat radial: mantle thickened and 

 distinctly double on the border, often papillose behind where the outer 

 told develops into a thickened flap; branchial opening with irregular 

 teeth; anal opening smooth or only slightly crenulate. 



(Group of Lampsilis alatus.) 



Shell obovate, strongly winged, subsolid, with a slight posterior and 

 superposterior ridge; epidermis thick, dark, showing irregular growth 

 lines; hinge teeth generally well developed; nacre dark imrple, female 

 shell greatly developed in post-basal region. Animal with very numer- 

 ous and tine ovisacs; marsupium large; inner gills united to abdominal 

 sac throughout. 



t LAMPSILIS ALATUS Say. 



Unio alatus Say, Nich. Encyc, II, 1816, pi. iv, fig. 2.— *Hildreth, Am. Jl. Sci., 

 XIV, 1828, p. 285, fig. 17.—" Say, Am. Conch., VI, 1834.—* Conrad, New F. W. 

 Shells, 1834, p. 67; Monog., VII, 1836, p. 57, pi. xxxi.— Sowerby, Conch. 

 Man., 1839, fig. 147.— *^ Anton, Verz. der Couch., 1839, p. 14.— 'Eeeve, 

 Couch. Syst., I, 1841, p. 118, pi. Lxxxix, fig. 8.— *C. B.Adams, Thompson's 

 History of Vermont, 1842, p. 166, fig. ; * L. and F. W. Shells of Vermont, 1842, p. 

 16, fig.—" Hanley, Test. Moll., 1842, p. 174; * Biv. Shells, 1843, p. 174.— *De 

 Kay, Zool. of N. Y., Pt. 5, 1843, p. 195.— ' Potiez and Michaud, Gall. Moll., 

 1844, p. 146, pi. Lvi, fig. 2.—* Catlow and Eeeve, Conch. Nom., 1845, p. 55. — 

 "KusTER, Conch. Cab., 1852, p. 15, pi. i, fig. 1. — "Dewey, Ninth Rep. N. Y. 

 Cab. Nat. Hist., 1856, p. 32.— "H. and A. Adams, Gen. Rec. Moll., II, 1857, 

 p. 498.— "Chenu, Man., 1859, II, p. 143, fig. 708.— * Sowerby, Conch. Icon., 

 XVI, 1866, pi. XLiv, tig. 242.—* Calkins, Pr. Ottawa Ac. N. Sci., 1874, p. 41.— 

 *Latchford, Tr. Ottawa F. N. Club, 1882, p. 52.— *B. H. Wright, Check 

 List, 1888.—* P.ETEL, Conch. Sam., Ill, 1890, p. 144. 



* Margarita ( Unio) alatus Lea, Syn., 1836, p. 11; 1835, p. 13. 

 "^ Margaron ( Unio) alatus Lea, Syn., 1852, p. 19; 1870, p. 28. 



* Lampsilis alatus Baker, Moll. Chicago, Pt. 1, 1898, p. 97, pi. xviii. 



* Unio alata Lamarck, An. sans Vert., VI, 1819, p. 76. — * Deshayes, Encyc. Meth., 



II, 1830, p. 583; *An. sans Vert., 2d ed., VI, 1835, p. 539; 3d ed., II, 1839, 

 p. 669. 

 "Mya alata, Eaton, Zool. Text-Book, 1826, p. 219.— * Wood, Index Test. (Rev.), 

 1856, p. 199, pi. I, supp. fig. 3. 



* Symplnjnota alata Lea, Tr. Am. Phil. Soc, III, 1830, p. 448; "Obs., 1834, I, p. 



62. — Short and Eaton, Transylvania ,11. , 1831, p. 80. — "Ferussac, Gner. 

 Mag., 1835, p. 25. 



* Lymnadia alata Swainson, Treat, on Mai., 1840, p. 265, fig. 48; * Exotic Couch., 



2d ed., 1841, p. 38, pi. vii. 



* My sea alata Swainson, Exotic Conch., 2d ed., 1841, p. 28, pi. vii. 



* Meta])te7-a alata Stimpson, Shells of N. Eng., 1851, p. 14. — * Conrad, Pr. Ac. N. 



Sci. Phila.', VI, 1853, p. 260. 

 '"? Metajjtera metapiera RxFiN'EsqvK, Ann. Gen. Sci., Brux, V, 1820, p. 300, pi. 

 Lxxx, figs. 20-22.— * Chenu, Bib. Conch., 1st ser., Ill, 1845, p. 15, pi. i, 

 figs. 20-22. 



