CHIEFLY OF THE UNITED STATES. 299 



Remarks. — There are four specimens before me, all of which have a mixture of 

 color, salmon, purple and greenish epidermal matter, which gives a singular clouded 

 aspect to the nacre of the interior. Hence the name. The salmon color prevails and 

 is very intense and beautiful in several of ihe specimens. In outline this species is 

 near to Weldonensis and Meclclenhergensis (nobis). It is more quadrate than either 

 and differs entirely in the color of the nacre. 



Unio datus. pi. 44, fig. 111. 



Testa Isevi, lato-elliptica, valde compressa, intequilaterali, postice obtuse angulari, antice rotundata ; 

 valvulis subcrassis, antice parum crassioribus ; natibus promiuulis ; epidermide rufo-fusca, 

 micanti, obsolete radiata ; dentibus cardinalibus parviusculis, sulcatis erectisque ; lateralibus 

 prelongis, subcurvis, lamellatis corrugatisque ; margarita nubila, salmonea et purpurea, et valde 

 iridescente. 



Shell smooth, broadly elliptical, very much compressed, inequilateral, obtusely 

 angular behind, rounded before ; valves somewhat thick, a little thicker before ; 

 beaks slightly prominent ; epidermis reddish-brown, shining and obscurely radiated ; 

 cardinal teeth rather small, sulcate and erect ; lateral teeth very long, somewhat 

 curved, lamellar and corrugate; nacre cloudy, salmon-color and pui'ple, and very 

 iridescent. 



Proc. Acad. Nat. Sci. 1868, p. 161. 



Hob. — Paw Creek, Beaver Co., and Long Creek, N. C, C. M. Wheatley. 



My cabinet and cabinet of Mr. Wheatley. 

 Diam. -8, Length 1-7, Breadth 3-2 inches. 



Shell smooth, broadly elliptical, very much compressed, inequilatei"al, obtusely 

 angular behind and rounded before; substance of the shell somewhat thick, a little 

 thicker before ; beaks slightly prominent ; ligament long, narrow and dark ; epidermis 

 reddish-brown, shining, obscurely radiated, witli distant distinct lines of growth ; 

 umbonial slope flattened; posterior slope slightly carinate; cardinal teeth rather 

 small, sulcate and erect; lateral teeth very long, somewhat curved, lamellar and 

 corrugate; antei'ior cicatrices distinct, large and well impressed; posterior cicatrices 

 distinct and moderately well impressed ; dorsal cicatrices nearly in the centre of 

 the cavity of the beaks; cavity of the shell shallow and wide; cavity of the beaks 

 very shallow; nacre cloudy, salmon-color and purple, and very iridescent. 



Remarks. — Three specimens are before me and they are all of the same regular 

 ellipse. In outline it is very close to suhelUpsls (nobis), and also to some varieties of 

 radiaius, Lam., but these totally differ in radiations and color of epidermis. The 

 nacre in all has a predominence of salmon color, but it it is mixed with purple and 



72 



