NO. 1205. SYNOPSIS OF THE XJ I A DES SIMPSON. 775 



tQUADRULA SPARSA Lea. 



*Unio sparsus LEA, Pr. Am. Phil. Soc., II, 1841, p. 82;' *Tr. Am. Phil. Soc., VIII, 

 1842, p. 242, pi. xxv, fig. 58; *Obs., Ill, 1842, p. 80, pi. xxv, fig. 58. * CON- 

 RAD, Pr. Ac. N. Sci. Phila., VI, 1853, p. 257. * H. and A. ADAMS, Gen. Rec. 

 Moll., II, 1857, p. 497. *CHENU, 111. Conch., 1858, pi. xxvi, figs. 2, 2a, 26. 

 * REEVE, Conch. Icon., XVI, 1864, pi. iv, fig. 14.* B. H. WRIGHT, Check List, 

 1888. *P.ETEL, Couch. Sam., Ill, 1890, p. 168. 



* Margaron (Unio) sparsus LEA, Syn., 1852, p. 22; 1870, p. 33. 



Holston aud Clinch rivers, Tennessee. 



tQUADRULA INTERMEDIA Conrad. 



* Unio intermedius CONRAD, Monog., VII, 1836, p. 63, pi. xxxv, fig. 2; *Pr. Ac. 



N. Sci. Phil., VI, 1853, p. 250. * HANLEY, Biv. Shells, .1856, p. 381, pi. xx, 

 fig. 28. * H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 497. * KUSTER, 

 Conch. Cab. Unio, 1861, p. 213, pi. LXX, fig. 6.* REEVE, Conch. Icon., XVI, 

 1864, pi. xin, fig. 48.* B. H. WRIGHT, Check List, 1888.* PJETEL, Conch. 

 Sam., Ill, 1890, p. 155. 



* Margaron ( Unio') intermedius LEA, Syn., 1852, p. 22; 1870, p. 33. 



* Unio kleiniantis KUSTER, Conch. Cab. Unio, 1861, p. 191, pi. LX, fig. 4. 



Tennessee Eiver system. 



tQUADRULA STAPES Lea. 



* Unio stapes LEA, Tr. Am. Phil. Soc., IV, 1831, p. 77, pi. vn, fig. 8.* Obs.,-1. 



1834, p. 87, pi. vii, fig. 8.* CONRAD, New F. W. Shells, 1834, p. 71.* FER- 

 USSAC, Guer. Mag., 1835, p. 28.* CONRAD, Monog., VII, 1836, p. 62, pi. xxxv, 

 fig. 1.* HANLEY, Test. Moll., 1842, p. 179; * Biv. Shells, 1843, p. 179, pi. 

 xxn, fig. 38. * CATLOW and REEVE, Conch. Nona., 1845, p. 64. * CONRAD, 

 Pr. Ac. N. Sci. Phila., VI, 1853, p. 258.* H. and A. ADAMS, Gen. Rec. Moll., 

 II, 1857, p. 497. CHENU, 111. Conch., 1858, pi. xv., figs. 5, 5o, 5b; "Manual, 

 1859, II, p. 142, fig. 997.* REEVE, Conch. Icon., XVI, 1864, pi. xin, fig. 52. 

 *B. H.WRIGHT, Check List, 1888. " PJETEL, Conch. Sam., Ill, 1890, p. 168. 



* Margarita ( Unio) stapes LEA, Syn., 1836, p. 15; 1838, p. 13. 



* Margaron ( Unio) stapes LEA, Syn., 1852, p. 22; 1870, p. 33. 



* Unio retusus SAY, Am. Conch., VI, 1834. 



* Unio stegarius KUSTER, Conch. Cab. Unio, 1861, p. 211, pi. LXX, fig. 3. 



Alabama and Toinbigbee rivers. 



Section THELIDERMA (Swainson, 1840) Simpson. 2 

 (Type, Unio lacJtrymosua Lea. ) 



Shell rounded, quadrate to rhomboid, solid, pustulous; beaks rather 

 prominent ; beak sculpture consisting of a few rather coarse, subparallel 

 ridges; anterior end rounded or slightly subtruncate above; base often 

 arcuate; posterior end truncate, high and angled behind the ligament; 

 epidermis scarcely rayed, never pointed; beak cavities rather deep. 



1 It is likely that this is only a small, rather smooth variety of tuberosus. 



2 Swainsou's first species of this group in the text of the Treatise is Unio irroratus, 

 and after this metanevrus and cyUndrwus. In the final classification in the same work 

 he includes in the group laclirymosns and pustulosus, and by the process of elimina- 

 tion I use the name in order to save coining a new one. 



