NO. 1205. SYNOPSIS OL< THE NAIADES SIMPSON. 7Q5 



tUNIO STONENSIS Lea. 



* Unio stonensls LEA, Pr. Am. Phil. Soc., I, 1840, p. 286 ; *Tr. Am. Phil. Soc., VIII, 



1841, p. 195, pi. vin, fig. 5; Obs., Ill, 1842, p. 33, pi. vin, fig. 5. "CONRAD, 

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

 II, 1857, p. 495.* CHENU, 111. Conch., 1858, pi. xxix, tigs. 7, la, 76.* Sow- 

 EKBY, Conch. Icon., XVII, 1868, pi. LXXXVI, fig. 462.* B. H. WRIGHT, Check 

 List, 1888. *P,ETEL, Conch. Sam., Ill, 1890, p. 168. 



* Mar gar on (Unio) stonensis LEA, Syn., 1852; 1870, p. 43. 



Stone Kiver, Tennessee. 



t UNIO LURIDUS Lea. 



*Unio luridus LEA, Tr. Am. Phil. Soc., X, 1852, p. 273, pi. xx, fig. 29; Obs., V, 

 1852, p. 29, pi. xx, fig. 29.* CONRAD, Pr. Ac. N. Sci. Phila , VI,' 1853, p. 251 ; 



* H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 494.* B. H. WRIGHT, Check 

 List, 1888.* P.ETEL, Conch. Sam., Ill, 1890, p. 158. 



*Margaron ( Unio) luridus LEA, Syn., 1852, p. 30; 1870, p. 48. 



Yadkin River, North Carolina; Georgia; Florida. 

 (Group of Unio discus.) 



Shell large, solid, compressed, subtriaugular; biangulate behind; 

 beak sculpture not seen ; beaks high, but not swollen ; epidermis dark, 

 rough; teeth heavy; laterals remote, club-shaped; nacre white, yel- 

 low or purple. 



Animal unknown. 



fUNIO DISCUS Lea. 



* Unio discus LKA, Tr. Am. Phil. Soc., VI, 1838, p. 74, pi. xvm, fig. 57 ; * Obs., II, 1838, 



p. 74, pi. xvm, fig. 51.* TROSCHEL, Arch, fur Naturg., V, 1839, Pt. 2, p. 237. 



* HANLEY, Test. Moll., 1842, p. 197 ; * Biv. Shells, 1843, p. 197, pi. xxn, fig. 12. 

 *CATLOW and REEVE, Conch. Nom., 1845, p. 58. * CONRAD, Pr. Ac. N. Sci. 

 Phila., VI, 1853, p. 248. * H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 

 494. *CHKNU, 111. Couch., 1858, pi. xix, figs. 6,60, 6&. * SOWERBY, Conch. 

 Icon., XVI, 1868, pi. i.xn, fig. 310. 'B. H. WRIGHT, Check List, 1888. 

 *P^TEL, Conch. Sam., Ill, 1890, p. 151. * FISCHER and CROSSE, Miss. Sci., 

 Pt. 7, II, 1894, p. 567. 



*Margaron (Unio) discus LEA, Syu., 1852, p. 31; 1870, p. 50. 



* Unio panacoensis, VON DEM BUSCH in Philippi, Abbild. und Besch., I, 1843, p. 75, 



pi. n. *KUSTER, Conch. Cab. Unio, 1861, pi. LXXXI, fig. 1. *P.*;TEL, Conch. 

 Sam., Ill, 1890, p. 162. 

 *Unio mexicanus SOWERBY, Conch. Icon., XVI, 1867, pi. LV, fig. 281. 



Mexico; Central America. 



(Group of Unio sloatianus.) 



Shell rhomboid, solid, inflated, with a well-defined posterior ridge 

 and a smaller, fainter one above, the posterior end being distinctly 

 biaugulate, nearly straight or slightly incurved on the base, 

 rounded in front; beaks only slightly elevated; beak sculpture not 

 observed ; surface of the valves covered with somewhat radiately plicate, 

 nodulous corrugations which become less pronounced in front; posterior 

 Proc. N. M. vol. xxii 45 



