474 K. J. Bush—MolhiM-a of Cape Hatter as. 



Pandora Carolinensis, sp. nov. 



Pandora, sp., Bush., Report U. S. Com. Fish and Fisherios, p. 8(3, for 1883, 1885. 



Shell of moderate size, triangular-ovate, with a short, acutely 

 angled posterior end and an elongated, slightly rostrated anterior end. 

 Valves very unequal, overlapping; the superior one very convex; 

 the inferior one flat or slightly concave. Beaks very small, curved 

 inward and backward, situated near the posterior end. Anterior dor- 

 sal margin very straight ; posterior very oblique, slightly concave just 

 behind the beaks ; ventral margin much swollen along the middle, 

 pretty regularly curved to near the anterior end where it is slightly 

 contracted and forms a short, narrow rostrum. Right valve the 

 larger, very convex, moderately thick, with a dull surface, roughened 

 by the irregular, sinuous lines of growth. Extending from the beaks 

 perpendicularly across the valve is a distinct, though slight, depres- 

 sion in the surface, in crossing which the lines of growth abruptly 

 curve downward. A prominent, rounded ridge runs from the beaks 

 to the anterior ventral margin, forming a narrow dorsal area crossed 

 by the lines of growth. Below the ridge the surface is a little con- 

 cave and forms a slight contraction in the margin, more apparent in 

 some specimens than in others. Anterior hinge plate is a little thick- 

 ened, very narrow ledge, on which the left valve rests, extending 

 nearly the entire length of the dorsal margin ; behind the beaks is a 

 thick, conspicuous, triangular process or tooth, which is concave next 

 the margin of the valve; in front of this, directly under the beaks, is 

 a narrow, oblique cavity, with the very narrow cartilage-pit in front 

 of it. Left valve considerably smaller and very thin, with a conspic- 

 uous furrow running out from beak, corresponding to the ridge in 

 the opposite valve, above which the valve bends slightly outward. 

 Besides the irregular lines of growth the surface is cut by numerous, 

 about fourteen, unequally distant, impressed, radiating lines. In 

 front of the beaks the edge of the valve is bent in at right angles, 

 forming a gradually widening area which laps over the opposite 

 valve ; directly under the beak is a thick, prominent, elongated, 

 oblique tooth, and a very much thinner, longer, less elevated, more 

 oblique, wedge-shaped one in front of it with the'narrow cartilage- 

 pit between ; extending from behind the beaks along the dorsal mar- 

 o-in is a rather delicate ridge, which in some specimens shows only as 

 a sli'i'ht thickening of the edge, and in others it is separated from it 

 and shows as a ridge or tooth. Pallial impression well marked ; 

 pallial line formed by a line of indistinct dots. Interior of the shell 

 very pearly. 



