﻿r.AMPSii.rs T63 



truncate behind ; the male shell is less full in the post-basal 



region, and is nearly rounded behind. 



Length 160, height to point of broken wing- 120, diam. 40 



mm. 



Entire Mississippi drainag^e as far south as Arkansas ; St. 



Lawrence drainag-e ; Red River of the North. 

 Type locality not given. 



Unio alatiis Say, Nich. Encyc, IL 18 17, pi. iv, fig. 2. — Hii,- 

 DRETH, Am. Jl. Sci., XIV, 1828, p. 285, fig. 17. — Conrad, 

 Monog., Vn, 1836, p. 57, pi. XXXI. — SowERBY, Conch. Man. 

 1839, fig. 147. — Reeve, Conch. Syst., L 1841, p. 118, pi 

 [XXXTX, fig. 8. — C. B. Adams, Thompson's Hist, of Ver- 

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

 1842, p. 16. fig. — PoTiEz and Michaud, Gall. Moll., 1844 

 p. 146, pi. Lvi, fig. 2. — KusTER, Conch. Cab., 1852, p. 15, pi 

 I, fig. I. — Chenu, Man., 1859, II, p. 143, fig. 708. — Sower- 

 BY, Conch. Icon.. XVI, 1866, pi. xliy, fig. 242. 



Margarita (Unio) alatus Lea, Syn., 1836, p. 11 ; 1838, p. 13. 



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



Lampsilis alatus Baker. Moll. Chicago, Pt. i, 1898, p. 97, pi. 

 XVIII. — Simpson, Syn., 1900, p. 567. 



Unio alata Lamarck, An. sans Vert.. VI, 1819, p. 76. 



Mya alata, Eaton, Zool. Text-Book, 1826, p. 219. — Wood, In- 

 dex Test. (Rev.), 1856, p. 199, pi. i, supp. fig. 3. 



Symphynota alata Lf..-\, Tr. Am. Phil. Soc. Ill, 1830, p. 448; 

 Obs., I, 1834, p. 62. 



Lymnadia alata Sv.^mnson, Treat, on Mai.. 184c, p. 265, fig. 

 48. 



Mysca alata Swatnson, Exotic Conch.. 2d ed., 1841, p. 28, pi. 



VII. 



Metaptcra alata Stimpson, Shells of N. Eng., 1851, p. 14. 

 Proptera alata Ortmann, Ann. Car. Mus., A^IIT, 1912, p. t,^t^. 

 ? Mctaptera >tirtapte>-a Rafinesoue, 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. 



