610 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii. 



tCYPROGENIA IRRORATA Lea. 



* Unio irroraius Lea, Tr. Am. Phil. Soc., Ill, 1830, p. 269, pi. v, fig. 5 ; * Obs., 1, 1834, 



p. 11, pi. V, fig. 5. — Short and Eaton, Transylvania Journ., 1831, p. 77. — 

 * Hanley, Test. Moll., 1842, p. 181 ; * Biv. Shells, 1843, p. 181, pi. xx, fig. 25.— 

 *Catlow and Keeve, Conch. Norn., 1845, p. 60.— *Chenu, 111. Conch., 18.58, 

 pi. X, figs. 3, 3rt, 36.—* Reeve, Conch. Icon., XVI, 1864, pi. xii, fig. 44.—* B. H. 

 Wright, Check List, 1888. 



* Margarita ( Unio) irroratus Lea, Syn., 1836, p. 16; 1838, p. 15. 



* Margaroii ( Unio) irroratus Lea, Syn., 1852, p. 22; 1870, p. 34. 



* Unio irrorata Deshayes, Encyc. Meth., II, 1830, p. 579.—* Deshayes, An. sans. 



Vert., 2d ed., VI, 1835, p. 547; 3d ed., II, 1839, p. 672. 



* Theliderma irrorata, Swainson, Tr. on Mai., 1840, p. 271, fig. 54a. 



* Unio rei-rucosus alhus Hildreth, Am. .11. Sci., XIV, 1828, p. 281. 



* Unio stegarius Say, Am. Conch., VI, 1834.—* Conrad, New F. W. Shells, 1834, p. 



71.—* Ferussac, Guer. Mag., 1835, p. 28.—* Conrad, Monog., X, 1838, p. 83, 

 pi. XLVi, fig. 1; *Pr. Ac. N. Sci. Phila., VI, 1853, p. 258.— *Eeeve, Conch. 

 Icon., XVI, 1864, pi. xi, fig. 45. 



* Unio stegarius var. irroratus Pjetel, Conch. Sam., Ill, 1890, p. 168. 



fCYPROGENIA IRRORATA var. PUSILLA Simpson.' 



Ohio, Cumberland, and Tennessee river systems; St. Francis and 

 Saline rivers, Arkansas? Eastern Iowa? The specimens reported 

 from the western localities may be G. aherti. 



tCYPROGENIA ABERTI Conrad. 



* Unio aherti Conrad, Pr. Ac. N. Sci. Phila., V, 1850, p. 10; * VI, 1853, p. 244; Jl. 



Ac. N. Sci. Phila., 1854, p. 295, pi. xxvi, fig. 1.—* B. H. Wright, Check List, 

 1888. 



* Margaron ( Unio) aberti Lea, Syn. 1870, p. 34. 



* Unio lamarckianus Lea, Tr. Am. Phil. Sci., X, 1852, p. 266, pi. xvii, fig. 20; " Obs., 



V, 1852, p. 22, pi. XVII, fig. 20.—* H. and A.Adams, Gen. Rec. Moll., II, 1857, 

 p. 496.— * SowERBY, Conch. Icon., XVI, 1868, pi. xcii, fig. 498.— * Pastel, 

 Conch. Sam., Ill, 1890, p. 156. 



* Margaron ( Unio) lamarckianus Lea, Syn., 1852, p. 23. 



* Uniopopenoi Call, Bull. Washb. Coll., 1, 1885, p. 49, pi. ii. 



Kansas; Missouri; Indian Territory; Arkansas. 



Genus OBLIQUARIA (Rafinesque 1820) Simpson. 

 (Type, Obliquaria reflexa Rafinesque.) 

 Ohliquaria Rafinesque, Ann. Gen. Sci. Phys. Brux., 1820, p. 301. 



Shell inflated, solid, oval, ending in a tolerably sharp point behind, 

 having a row of large, compressed, longitudinal knobs running from 

 the beaks to the center of the base, those of one valve alternating in 

 position with the knobs of the other, and a well- developed posterior 

 ridge, the space between the ridge and knobs somewhat excavated; 

 posterior sloj)e and sometimes the entire shell more or less corrugately 

 sculptured; beaks prominent, incurved and pointed slightly forward 

 toward a tolerably well-developed lunule; beak sculpture strong, con- 



' A peculiar, dwarfed variety, about one-half the size of the ordinary form and 

 much inflated, from the Green River, Kentucky. 



