30 NEW UNIONID.E OF THE 



Remarks. — There are three specimens of this .small, robust species betbre me. 

 Neither of these had the soft parts included. It it among the smallest of the genus, 

 and is nearly allied to punvinuhis (nobis), but is rather smaller and more oblique. The 

 color of the epidermis is also vei-y different, the j^itnvinuhis being of a dark brown, 

 while this is yellowish, and passing into golden yellow on the posterior portion. The 

 lateral teeth are thick and disposed to duplicature in the right valve. Very indistinct 

 capillary rays may be observed before the umbonial slope, on all the three specimens 

 under examination. This may be more observable in better specimens, neither of 

 these being perfect enough to give the character of the tips of the beaks. 



Unio hepaticus. pi. 57, fig. 173. 



Tesfil lievi, ovato oblonga, compressa, posticc late biangulata, inaequilaterali; valvulis subtenuibus ; natibus 

 prominulis; epidermide micante, hepatica, vcl eiadintil vcl obsolete radiata ; dontibus cardinalibus 

 parvis, subelevatis, striatisj, in utroque valvule duplicibus; lateralibiis longis, lamellatis subreotisque ; 

 raargaritd purpurascente et vald^ iridescente. 



Shell smooth, ovately oblong, compressed, broadly biangular behind, inequilateral ; 

 valves somewhat thin ; beaks a little prominent ; epidermis shining, browmish liver 

 color, without rays, or obsoletely rayed ; cardinal teeth small, slightly raised, striate 

 and double in both valves ; lateral teeth long, lamellar and nearly straight ; nacre 

 purple and very iridescent. 



Proc. Acad. Nat. Sci. 1859, p. 154. 



j£ab. — Salkahatchee River, South Carolina. J. Postell. 



My calmiet and cabinet of Mr. Postell. 

 Diam.-6, Length 1-3, Breadth 2-3 inches. 



Shell smooth, ovately oblong, disposed to be obovate, compressed, broadly biangular 

 behind; substance of the shell somewhat thin; beaks a little prominent ; ligament 

 rather small and dark brown ; epidermis shining, brownish liver color, striate, without 

 rays or very obscurely rayed, and with rather distant marks of growth; umbonial 

 slope slightly raised and obtusely angular ; posterior slope narrow, raised into a well 

 defined keel ; cardinal teeth small, slightly raised, striate, crenulate and double in 

 both valves, lateral teeth long, lamellar and nearly straight ; anterior cicatrices dis- 

 tinct, rather large and well impressed ; posterior cicatrices confluent and slightly 

 impressed; dorsal cicatrices well impressed and placed above the cavity of the 

 beaks ; cavity of the shell shallow and wide ; cavity of the beaks vei'y shallow 

 and rounded ; nacre purplish and very iridescent. 



BemarJcs. — I have eight specimens before me, but unfortunately none in alcohol or 

 with perfect beaks. This species belongs to the complanalus group, and is j^erhaps, 

 most nearly allied to fumatus (nobis). It is not, however, so thick in the substance of 

 the shell, and it is more biangular and higher in the posterior slope ; the color also of 

 the epidermis is not quite so dark. All the specimens before me are more or less pur- 

 plish in the nacre. Two are somewhat salmon colored in the cavity of the beaks. 



