FRESHWATER VND LAND SHELLS, '.'(iii 



Unio fkaternus. PI. XVI. Fiff. 1"). 



Testd hevi, ellipticd, compresad, striata, valde inequilaterali, postice subbianetulari} valvulis subcrassis; 

 natibus prominulis ; epidermidt tenebroso-fuscd ; dentibus cardinalibus parvis, tubereulatis, striatis; laterali- 

 bus prselongis subcurvisqui : margaritd vel alba vel purpurea et iridescente. 



Shell smooth, elliptical, compressed, striate, very inequilateral, subbiangular behind; valves rather thick; 

 beaks somewhat prominent; epidermis dark-brown; cardinal teeth small, tuberculate, striate; lateral teeth very 

 long and somewhat curved; nacre white or purple and iridescent. 



Hab. Columbus, Georgia, Dr. Boykin; Abbeville District, S. C, J. P. Barratt, M. D. 

 My cabinet and cabinet of Dr. Barratt. 

 Diam. .0, Length 1.3, Breadth 1.1 inches. 



Slid! smooth, elliptical, compressed, striate, very inequilateral, subbiangular behind, 

 obtusely rounded before, Battened on the sides; substance of the shell somewhat -thick, 

 thinner behind; beaks somewhat prominent and placed near to the anterior margin; 

 ligament long and rather thick; epidermis very dark-brown, darker on the posterior slope, 

 with distant marks of growth; posterior slope compressed, with fold-like wrinkles, and 

 raised into a carina ; umbonial slope obtusely angular; cardinal teeth small, tuberculate 

 and striate; lateral teeth very long, somewhat curved, thicker at the posterior end and 

 separated from the cardinal tooth; anterior cicatrices distinct; posterior cicatrices con- 

 tinent; dorsal cicatrices placed in a row on the interior of the plate; palleal cicatrix 

 impressed; cavity of the shell very shallow; cavity of the beaks very shallow and rounded; 

 nacre white or purple and iridescent. 



Remarks. — This species belongs to the group of which U. compianatus is the type. It 

 is closely allied to 17. Hopetonensis, (Nobis,) but diners in being more elliptical in the out- 

 line, and having a less elevated carina, and in the cardinal teeth, which are not compressed. 

 The outline is more that of Unio Hembeli, Con., but it is not so thick a shell, and does 

 not possess the coarse folds on the posterior slope, which in that species distinguish it so 

 well. The Hembeli is also darker, the stria) coarser, and the umbonial slope more rounded. 

 Of the si\ specimens before me, two are white, three purple, and one slightly salmon 

 coloured. The margin is broad and dark coloured. 



Umo Cuvif.rianus. PI. XVI. Fig. 16. 



'/' ! .' bi i, ' Uiptit ", i onvt i <'. im juilaterali, postice obtuse angulatd; valvulis eras sis ; natibus prominulis; 

 mii/> nitidd, cast aneo-f used } dentibus cardinalibus magnis crenulatisque; lateralibus prselongis sub- 



: • nti ii. 



[ Bmooth, elliptical, convex, inequilateral, obtusely angular behind; valves thick; beaka a little prominent; 



epidermis shining, chestnut-brown; cardinal teeth large, crenulate; lateral teetb very long and somewhat curved; 

 nacre silvery white. 



Hab. Washington county, Georgia, Rev. G. White. 

 Cabinet of Major Lc Conte. 

 Diam. 1.5, Length 2.2, Breadth 3.9 inches. 



Sluli smooth, elliptical, convex, inequilateral, obtusely angular behind, inflated over the 

 umb of the shell very thick; beaks but slightly prominent and submedial 



