﻿184 I.AMPSII.IS 



Unio Icrznssimus Conrad. New F. W. Shells, 1834, p. 70. — • 

 Hani.ey, Biv. vShells, 1843, p. 174, pi. xxi, fig. 41. — Sower- 

 BY, Conch. Icon.. XVI, 1866, pi. xlvi, fig^. 250. 



Margarita (Unio) l(C7*issim'it'S Lka, Syn.. 1836, p. 11; 1838. 



P- 13- 



Margaron (Unio) l(C7'issinvush}:A, Syn., 1852. p. 19; 1870, p. 28. 



Lampsilis hrz-issimus Simpson, Syn., 1900, j). 574. 



Proptera icci'issiina ()rtmann, Ann. Car. Mns., \'III, 1912, ]). 



324- 

 Unio ohiocnsis Say, .\m. Conch., W, 1834. — Kuster, Conch. 



Cab., 1866, p. 20, pi. LXix, fig. 5. 

 Syniphynota ohiocnsis Ferussac, Guer. Mag.; 1835, p. 25. 

 Metaptcra ohiensis Conrad, Pr. Ac. N. Sci. Phila., VI., 1853, 



p. 260. 

 Unio discoideus Sowerby, Conch. Icon.. XVI. 1866, pi. i.iii, 



fig:- 275. 



Generally a little less elongated and more brilliant than L. 

 gracilis, and it has feeble radial sculpture and a higher wing. 

 Its nacre is usually darker than that of gracilis. 



Lampsius jNi'XATA (Lea). 



Shell somewhat trapezoidal, being truncate on the posterior 

 slope and narrowed in front, thin, subinfiated, having its great- 

 est diameter just behind ttie center; dorsal wing probably high 

 in voung shells ; posterior ridge high and widely rounded ; l^eaks 

 low and compressed, their sculpture not seen ; epidermis green- 

 ish-olive to dark brownish, scarcely shining, nearly or quite 

 rayless ; in young shells there is often one or two faint, wide, 

 dark rays on the posterior slope ; left valve with a feebly de- 

 veloped, elongated pseudocardinal and two short, remote lat- 

 erals ; right valve with one faint, elongated pseudocardinal and 

 one high, short, truncated lateral ; beak cavities shallow, with 

 a row of irregular, large scars ; adductor scars shallow, the an- 

 terior ones large ; nacre rich purple, iridescent behind. There 

 seems to be but little difference between shells of the male and 

 female. 



