UNITED STATES AND NORTHERN MEXICO. 17 



striate; lateral teeth very long, lamellar and nearly strai-lit ; nacre wliito, purplLsli 

 or salmon color and very iridescent. 



Proc. Acad. Nut. Sci. 18."i9, p. 171. 



//«?,._ Savannah River, near Savannah, Geougia. Rev. G. White and xMajor 

 Le Conte. 



My cabinet and cabinets of Mr. White and Major Le Conte. 

 Di^„,. .5^ Length Vl, Breadth 2 3 inches. 



Shell smooth, transverse, compressed, obtusely angular behind, rounded before and 

 very inequilateral ; substance of the shell rather thin, beaks slightly prominent ; 

 ligament rather thin and light brown ; epidermis yellowish or yellowish brown, 

 shining, with very distant marks of growth, and rayed over the whole disk ; umboiiial 

 slope slightly raised and obtusely angular; posterior slope very long, narrow, sub- 

 carinate, striate, with two indistinct impres.sed lines on each valve from the beaks to 

 the posterior margin ; cardinal teeth small, rather compressed slightly raised, striate ; 

 lateral teeth very long, lamellar and nearly straight ; anterior cicatrices distinct and 

 moderately well impressed ; posterior cicatrices confluent and slightly impressed ; 

 dorsal cicatrices in a row situated across the centre of the cavity of the beaks ; cavity 

 of the shell shallow and wide; cavity of the beaks very shallow and obtusely angular ; 

 nacre white, purplish, salmon color and very iridescent. 



EemarJcs.—l have four specimens of this species before me. None were recuived 

 with the soft parts. It belongs to the comiJlanaius group, but is wider than that 

 species. It is not so wide as a^icjustatus (nobis), and is more yellow and rayed. It 

 is also near to Duitovianus (nobis), but not nearly so wide. It is more carinate on 

 the posterior slope than either of the above named species. Like complanatm it 

 varies in the nacre. Of the four specimens before me, one is white, two are purpli.sh 

 and one is salmon color. The marks of growth are very distinct, and the fnie green 

 rays cover the whole disk. In the older ones the posterior slope becomes rugose with 

 strias and is dark brown. 



Unio verutus. pi. 53, fig. 160. 



Testa Ixvi, transversa, subinflata, ad latere planulata, postici- obtus6 angulata, antice ro'undrtta et vald^- 

 inKquilaterali ; valvulis crassiusculis, antic6 paulispcr crassioribus ; natibus prominulis, ad apices crebre 

 undulatis ; epidermide rufo-fusca, radiata vel eradiata ; dentibus cardinalibus subgrandibus, compressis, 

 subelevatis, striatis, in utroquc valvulo duplicibus ; lateralibus prselongis, lamellatis, subcrassis subeur- 

 vis(iue ; luargarita vel alba vel salmonia vel purpurasccnte et valdu iridescente. 



Shell smooth, transverse, rather inflated, flattened at the side, obtu.sely angular 

 behind, rounded before and very inequilateral; valves somewhat thick, slightly 

 thicker before; beaks a little prominent, at the tips closely undulate; epidermis red- 

 dish brown, sometimes radiate and sometimes without rays; cardinal teeth rather 

 large, compressed, rather raised, striate and double in both valves; lateral teeth very 



