NO. 1205. SY^'OPSIS OF THE NAIADES— SIMPS0:N'. 705 



tUNIO STONENSIS Lea. 



* Unio stonensis Lea, Pr. Am. Phil. Soc, I, 1840, p. 286; * Tr. Am. Phil. Soc.,VIII, 



1841, p. 19.3, pi. VIII, fig. 5; Obs., Ill, 1842, p. 33, pi. viii, fig. 5.—* Conrad, 

 Pr. Ac. N. Sci.Phila., VI, 1853, p. 258.—'' H. and A. Adams, Gen. Eec. Moll., 

 II, 1857, p. 495.— *Chenu, 111. Conch., 1858, pi. xxix, figs. 7, 7a, 7&.— * 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 Eiver, 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. Eec. Moll., II, 1857, p. 494.—" B. H. Wright, Check 

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



* Manjaron ( Unio) liiridas Lea, Syn., 1852, p. 30; 1870, p. 48. 



Yadkin Eiver, North Carolina j Georgia; Florida. 

 (Group of Unio discus.) 



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

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

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

 low or purple. 



Animal unknown. 



fUNIO DISCUS Lea. 



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



p. 74, pi. xviii, fig. 51.—* Troschel, Arch, fiir Naturg., V, 1839, Pt. 2, p. 237.— 

 *Hanley, Test. Moll., 1842, p. 197; *Biv. Shells, 1843, p. 197, pi. xxii, fig. 12.— 

 *Catlow and Eeeve, Conch. Nom., 1845, p. 58. — * Conrad, Pr. Ac. N. Sci. 

 Phila., VI, 1853, p. 248.—* H. and A. Adams, Gen. Eec. Moll., II, 1857, p. 

 494. — *Chenu, 111. Conch., 1858, pi. xix, figs. 6,6a, 66.— * Sowerby, Conch. 

 Icon., XVI, 1868, pi. i.xii, 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, Syn., 1852, p. 31; 1870, p. 50. 



* Unio panacoensis, von dem Busch in Philippi, Abbild. und Besch., I, 1843, p. 75, 



pi. II. — *Kuster, Conch. Cab. Unio, 1861, pi. lxxxi, fig. 1. — *PiETEL, 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 

 biangulate, 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 



