70 NEW UXIONIP.i: OF THE 



rays, but the young may have them partially. The posterior slope is iisuall\- lighter 

 in color. 



Unio rubellinus. pi. 13, tig. 51. 



Testa plicatii, transversa, subtriangulari, subinfiata, valde inEequilaterali, postice acute angulati, antice 

 rotundata ; Talvulis subcrassis, antice crassioribus ; uatibus prominulis, ad apices undulatis; epider- 

 mide rubiuscula, nitida, radiata et maculata ; dentibus cardinalibus parvis, erectis acuminatisque ; 

 lateralibus longis, lamellatis subrectisque ; margarita rubida et iridescente. 



Shell folded, transverse, subtriangular, rather inflated, very inequilateral, acutely 

 angular behind and rounded before ; valves rather thick, thicker before ; beaks some- 

 what prominent, undulate at the tip ; epidermis a little reddish, bright, radiated and 

 spotted ; cardinal teeth small, erect and sharp ; lateral teeth long, lamellar and nearly 

 straight ; nacre reddish and iridescent. 



Proc. Acad. Nat. Sci. 1857, p. 33. 



Hah. — Othcalooga Creek, Gordon County, Georgia. Bishop Elliott. 



My cabinet and cabinet of Bishop Elliott. 

 Diam. -6, Length 7, Breadth 1-G inches. 



Shell folded, transverse, subtriangular, rather inflated, very inequilateral, acutely 

 angular behind, and constricted at the posterior basal margin, obliquely rounded 

 before, with small folds on the posterior slope and towards the posterior basal mar- 

 gin; substance of the shell rather thick, much thicker before; beaks somewhat 

 prominent, with a few irregular undulations at the tip ; ligament very short and thin ; 

 epidermis a little reddish, bright, obsoletely radiate and marked with minute arrow- 

 head like spots ; umbonial slope angular ; cardinal teeth small, erect, very sharply 

 pointed, single in the right and double in the left valve ; lateral teeth long, lamellar, 

 nearly straight, and enlarged at the posterior end : anterior cicatrices distinct and 

 deeply impressed; posterior cicatrices distinct; dorsal cicatrices placed across the 

 centre of the cavity of the beaks ; cavity of the shell rather deep ; cavity of the beaks 

 rather shallow and subangular ; nacre reddish, disposed to salmon color and iridescent. 



Soft Parts. — Branchial uterti-s occupying nearly the whole length of the outer 

 branchiae in rather large ovisacks, having on the lower margin a rather wide 

 reddish brown border. Branchice small, rather thick, nearly straight below, the inner 

 ones slightly the larger, free nearly half the length of abdominal sack. Rilpi very 

 small, subelliptical, united only at the upper part of the posterior edges. Mantle 

 thin, thickened at the margin, having the edges dark brown. Brancliial oj^ening 

 small, with small dark brown papillae on the inner edges. Anal opening rather large, 

 with brownish crenulations on the inner edges. Super-anal opening rather long, edge 

 slightly colored within, united below for a short distance. Color of the mass whitish. 



Byssm. — In all the specimens which have come under my notice (four adults) 

 there remains on the infei'ior mesial portion of the foot, a linear cicatrix, extending 



