98 NEW DNIONID^ OF THE UNITED STATES. 



Unio Beadleianus. pi. 14, fig. 242. 



Testil lasvi, subrotunda, ventricosa, subajquilaterali, antice rotundata, postice obtuse angulatil ; valvulis 

 crassis, antice crassioribus; natibus subelevatis, incurvis; epidermide tenebroso-fusca, obsolete radiata 5 

 dentibus cardinalibus magnis, erectis, compres.sis cnrrugatisque ; lateralibus crassis, curtis corrugati-s- 

 que ; raargaritil vel alba vel rosea et irideseente. 



Shell smooth, subrotund, ventricose, nearly equilateral, rounded before and obtusely 

 angular behind; valves thick, thicker before; beaks somewhat raised and incurved; 

 epidermis dark brown, obscurely rayed ; cardinal teeth large, erect, compressed and 

 corrugate ; lateral teeth thick, short and corrugate ; nacre white or rose color, and 

 iridescent. 



Proc. Acad. Nat. Sci. 1861, p. 39. 

 Eab. — Pearl River, Jackson, Mississippi. Rev. E. R. Beadle. 

 My cabinet and cabinets of Rev. Mr. Beadle, Mr. Wheatley and Dr. Hartman. 

 Diara. 1, Length 1-5, • Breadth 1-8 inch. 



Shell smooth, subrotund, ventricose, nearly equilateral, rounded before and obtusely 

 angular behind; substance of the shell thick, thicker before; beaks somewhat raised 

 and incurved ; ligament short, thick and dark brown ; epidermis dark brown, without 

 rays, or obscurely radiate and with distant marks of growth ; umbonial slope raised 

 into an obtuse angle ; posterior slope wide, flattened, with an obscure furrow in each 

 valve ; cardinal teeth large and massive, erect, compressed and cotrugate ; lateral 

 teeth thick, short, corrugate, disposed to duplication in the left as they are in the 

 right valve ; anterior cicatrices distinct, rather small and very deeply impressed ; 

 posterior cicatraces nearly distinct, rather large and well impressed ; dorsal cicatrices 

 placed nearly in the centre of the beaks; cavity of the shell deep and rounded; 

 cavity of the beaks deep and obtusely angular; nacre white or rose color, and 

 iridescent. 



Remarlcs. — This species very closely resembles circuhi>i (nobis), but may be distin- 

 guished at once by the angle on the umbonial slope, by its being higher in the beaks, 

 and by the color of the epidermis, which is more rufous in the Beadleianus. There 

 is also a diiFerence in the rose color of the nacre. In both species, I believe, the 

 white color prevails; it certainly does in the circulm. Of the four specimens before 

 me, two are white and two rose color, one of the latter being rather intense, and the 

 other only having a blush. The position of the color differs from that in circulus, 

 being spread over the nacre, while in the circulus, it is usually a tint in the centre of 

 the cavity. 



Specimens were sent by the Rev. Mr. Beadle, of Hartford, Connecticut, to Mr. 

 Wheatley, and I have great pleasure in dedicating the species to the gentleman who 

 discovered it, and to whom our cabinets are indebted for their possession. 



