FRE^SH WATEII AND LAND SHKLI.S. 19 



Unio fraternus. pi. XVI. Fi<r. 15. 



Testa Ixvi, e/fiplicd, rnmpressii, striata, vulde ineqiiilafera/i, postice snblnans^tihiri; vahnilis SKbcrassis ; 

 natibus promiaulis : cpidirmide tmebroso-fttsca ; dcntibus cardiiialibus parvis, tuberculalis, striatis ; lutcrali- 

 bus prselongis subcnrvisqur ; margaritd vel albci v el purpurea et iridescenle. 



Shell smoolh, elliptical, compressed, striate, very inequilateral, siibbiaiigular behind; valves rather thick; 

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

 lon^ 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. .6, Length 1.3, Breadth 1.4 inches. 



Shell smooth, elliptical, compressed, striate, very inequilateral, subbiangular behind, 

 obtusely rounded before, flattened 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- 

 fluent; dorsal cicatrices placed in a row on the interior of the plate; palleal cicatri.v 

 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. complainilns is the type. It 

 is closely allied to U. Hopctonensis, (Nobis,) but differs in being more elliptical in the out- 

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

 The outline is more that of Vnio HcmhcU, 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 HembcH is also darker, the strice coarser, and the umbonial slope more rounded. 

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

 coloured. The margin is broad and dark coloured. 



Unio Cuvierianus. PI. XVI. Fig. 16. 



Testa Isevi, eliipticd, conveicd, inequilaterali, poslice obtuse angulald; vuhulis crassis ; natibus prominvlis} 

 epidermide nitidd, castaneo-fusrd ; dentibus cardinuUbus magnis crenuhttisque ; lalera/ibus praslongis sub- 

 curvisque; margaritd arg^nted. 



Shell smooth, elliptical, convfex, inequilateral, obtusely angular behind; valves thick; beaks a little prominent; 

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

 nacre silvery white. 



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

 Cabinet of Major Le Conte. 

 Diam. 1.5, Length 2.2, Breadth 3.9 inches. 



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

 umbones; substance of the shell very thick; beaks but slightly prominent and submodiiil; 



