388 MOLLUSCA. 
Inhabits Townsend’s Harbour, and Straits of De Fuca, Oregon. 
The only species to which this bears any resemblance is S. viridis, 
which has nearly the same hinge and general form, but which is a 
more delicate and more slender shell, proportionally. 
Figures 501, 501 a, lateral and dorsal views of the shell; 501 4, 
hinge, with the interior. 
SoLEN scaLprum (Gould). 
Testa transversa, oblonga, retrorsum dilatata, fere unilateralis, tenurs, 
lucida, epidermide flavo-viridi, nitido, iridescente induta ; latere an- 
tico sub-acuto, oblique rotundato ; latere postico semicirculart: cardo 
dentibus duobus contiguis, divergentibus in valva dextra ; dente subu- 
lato, arcuato, in valva sinistra ; margine cardinal costa alba submar- 
ginali suffulto: interior albida. 
Solen scalprum, Goutp; Proceed. Boston Soc. Nat. Hist., i, 214. 
May 1850. Expedition Shells, 74. 
Sue xz thin, fragile, translucid, glistening with iridescent reflections ; 
epidermis pale yellowish-green ; lines of growth very delicate, with 
vestiges of radiating strie, transversely elongated, widening poste- 
riorly ; ventral and dorsal margins rectilinear ; posterior end circularly 
rounded; beaks at the anterior fifth; anterior end rounded obliquely 
upward, meeting the dorsal margin, which slopes a little, so that the 
tip is above the middle; posterior umbonal slope tumid. Interior 
broadly gaping, bluish-white. Hinge very delicate, having two con- 
tiguous, diverging, and divaricating, narrow, compressed teeth, in the 
right valve; a subulate, recurved one, and the vestige of a second at 
its anterior base, in the left valve; anterior hinge margin strengthened 
by an oblique rib; posterior dorsal edge simulating a long, linear, 
white tooth. 
Length an inch and three-quarters; breadth five-eighths of an inch; 
height three-tenths of an inch. 
Obtained at Singapore. 
A delicate and peculiar shell, allied to S. costatus, Say, though its 
