610 PROCEEDINGS OF THE NATIONAL MUSEUM. 



tCYPROGENIA IRRORATA Lea. 



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



p. 11, pi. v, fig. 5. SHOUT arid EATON, Transylvania Journ., 1831, p. 77. 

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

 *CATLOW and REEVE, Conch. Nom., 1845, p. 60. *CHENU, 111. Conch., 1858, 

 pi. x, figs. 3, 3a, 35.* REEVE, Conch. Icon., XVI, 1864, pi. XH, fig. 44.* B. H. 

 WRIGHT, Check List, 1888. 



* Maryarita ( Unio) irroratus LEA, Syn., 1836, p. 16; 1838, p. 15. 



* Maryaron ( Unio) irroratus LEA, Syu., 1852, p. 22; 1870, p. 34. 



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



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



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



* Unio rerrucosus albus HILDRETH, Am. Jl. Sci., XIV, 1828, p. 281. 



* Unio steyarius SAY, Am. Conch., VI, 1834." CONRAD, New f. W. Shells, 1834, p. 



71. * FERUSSAC, Guer. Mag., 1835, p. 28. ' CONKAD, Monog., X, 1838, p. 83, 

 pi. XLVI, fig. 1; *Pr. Ac. N. Sci. Phila., VI, 1853, p. 258. * REEVE, Conch. 

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



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



tCYPROGENIA IRRORATA var. PUSILLA Simpson. 1 



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

 Saline rivers, Arkansas? Eastern Iowa? The specimens reported 

 from the western localities may be C. aberti. 



tCYPROGENIA ABERTI Conrad. 



* Unio aberti 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 lamarcUanus LEA, Tr. Am. Phil. Sci., X, 1852, p. 266, pi. xvir, fig. 20; * Obs., 



V, 1852, p. 22, pi. xvn, fig. 20.* H. and A. ADAMS, Gen. Rec. Moll., II, 1857, 

 p. 496.* SOWERBY, Couch. Icon., XVI, 1868, pi. xcn, fig. 498." P.-ETEL, 

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



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



* Unio popenoi CALL, Bull. Washb. Coll., 1, 1885, p. 49, pi. n. 



Kansas; Missouri; Indian Territory; Arkansas. 



Genus OBLIQUARIA (Rafinesque 182O) Simpson 



(Type, Obliquaria rejlejca Rafinesque.) 

 Obliquaria 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 slope 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. 



