NO. 1205. SYXOl'SIS 01' Till-: XMMtESSlML'SOS. 5<)7 



frequently imperfect or nearly wanting; laterals remote ; anterior muscle 

 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 

 with large branchije; marsupium consisting of numerous, generally 

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

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

 lold develops into a thickened flap; branchial opening with irregular 

 teeth; anal opening smooth or only slightly crenulate. 



(Group of Lampsilis alatns.) 



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 purple, female 

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

 ous and fine 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. VV. 

 Shells, 1834, p. 67; Monog., VII, 1836, p. 57, pi. xxxi. * SOWKRBY, Conch. 

 Man., 1839, fig. 147. "ANTON, Verz. der Conch., 1839, p. 14. *REEVK, 

 Conch. 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. i.vi, fig. 2. * CATLOW and REEVE, Conch. Nora., 1845, p. 55. 

 "KusxER, Conch. Cab., 1852, p. 15, pi. i, fig. 1. *!)EWEY, 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, fig. 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. 

 * Maryaron (Unio) atatits LEA, Syn., 1852, p. 19; 1870, p. 28. 



* Lampsilis alatns BAKER, Moll. Chicago, Pt. 1, 1898, p. 97, pi. xvm. 



* 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. 

 *Symphyiiota alata LEA, Tr. Am. Phil. Soc., Ill, 1830, p. 448; *()bs., 1834, I, p. 



62. SHORT and EATON, Transylvania Jl., 1831, p. 80. * FERUSSAC, Guer. 



Mag., 1835, p. 25. 



* Lymnadia alata SWAINSON, Treat, on Mai., 1840, p. 265, fig. 48; * Exotic Conch., 



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



* Mysca alata SWAINSON, Exotic Conch., 2d ed., 1841, p. 28, pi. vn. 



* Metapiera alata STIMPSON, Shells of N. Eng., 1851, p. 14. * CONRAD, Pr. Ac. N. 



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



*? Metaptera metaptera RAFINESQUK, Ann. Gen. Sci., Brux, V, 1820, p. 300, pi. 

 i.xxx, figs. 20-22. * CHKXU, Bib. Conch., 1st ser., Ill, 1845, p. 15, pi. I, 

 figs. 20-22. 



