PROCEEDINGS or THJ: NATIONAL MUSEUM. VOL.XXH. 



fUNIO SPISSUS Lea, 



* Unio spissu* LEA, Pr. Ac. Nat. Sci. Phila., Ill, 1859, p. 112; *J1. Ac. Nat. Sci. 



Phila., IV, 1859, p. 208, pi. xx v, fig. 89 ; * Obs., VII, 1859, p. 26, pi. xxv, fig. 89. 



* SOWERBY, Conch. lion.. XVI, 1868, pi. i.xxxvm, fig. 476.* 15. H. WRIGHT, 

 Check List, 1888. *P.TEL, Couch. Sam., Ill, 1890. p. 168. 



*Margaron (Unio) spissus LKA, Syn., 1870, p. 41. 



Georgia. 



(Group of I'niofisheriantiN.) 



Shell elongated, rather thin,- subcompressed, pointed behind and 

 sometimes slightly biangulate 5 posterior ridge generally well developed ; 

 beaks low, the sculpture consisting of a few coarse, slightly irregular 

 ridges which run nearly parallel with the growth lines, generally 

 heavier where they cross the posterior ridge; epidermis sometimes 

 rayed, shining; pseudocardinals usually compressed; laterals long, 

 straight, and lamellar; beak cavities very shallow and containing two 

 or three dorsal scars at some distance behind the beaks; muscle scars 

 well marked, the posterior ones elongated; nacre generally dull. Ani- 

 mal with the gills greatly elongated, inner the larger, more or less free 

 from the abdominal sac ; marsupium occupying nearly or quite the whole 

 length of the outer branchia*; palpi elongated; mantle thin, thicker on 

 the edge. 



tUNIO LANCEOLATUS Lea. 



* Unio lanceolalus LEA, Tr. Am. Phil. Soc., 1828, p. 266, pi. in, fig. 2 ; * Obs., 1. 1834, 



p. 8, pi. in, fig. 2.* CONRAD, New F. W. Shells, 1834, p. 70. TERUSSAC, 

 Guer. Mag., 1835, p. 26. * CONRAD, Monog. Ill, 1836, p. 32, pi. xiv., fig. 2. 

 *HANLEY, Test. Moll., 1842, p. 204; *Biv. Shells., 1843, p. 204, pi. xx, fig. 60; 

 xxn, fig. 26. * CATLOW and REEVE, Conch. Nom., 1845, p. 60. * CONRAD, Pr. 

 Ac. Nat. Sci. Phila., VI, 1853, p. 251. *H. and A. ADAMS, Gen. Rec. Moll., II, 

 1857, p. 491. *CHENU, 111., Conch. 1858, pi. vm, fig. 1, la, 16. *KUSTEK, 

 Conch. Cab. Unio., 1861, p. 204, pi. Lxvm^fig. 4.* SOWERBY, Conch. Icon., 

 XVI, 1866, pi. XLIII, fig. 236. *B. H. WRIGHT, Check List, 1888. * PJETKL, 

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



* Margarita ( Unio) lanceolatus LEA, Syn., 1836, p. 35; 1838, p. 24. 



*Margaron ( Unio) lanceolatus LEA, Syn., 1852, p. 36; 1870, p. 57. 



*Unio lanceolata DESHAYES, Enc. Me"th., II, 1830, p. 585; * An. sans Vert., 2d ed., 

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



North Carolina; Virginia. 



|UNIO VIRIDULUS Lea. 1 



* Unio viridulm LEA, Pr. Ac. Nat. Sci. Phila., VII, 1863, p. 193; *J1. Ac. Nat. Sci. 



Phila., VI, 1866, p. 10, pi. in, fig. 17; * Obs., XI, 1867, p. 14, pi. m, fig. 17. 



* B. H. WRIGHT, Check List, 1888. 



* Margaron ( Unio) viridulus LEA, Syn., 1870, p. 58. 



Neuse Eiver, near Ealeigh, North Carolina. 



1 A young shell, no doubt, which in texture and appearance is much like U.danceo- 

 latus, but is bright green and not so pointed behind. 



