CLASS PELECYPODA 
159 
Liocyma scammoni Dali, 1871. 
Plate 6, fig. 7. 
Amer. Jour. Conch., 7:145; pi. 14, fig. 9. 
Shell most resembling L. fluctuosa, but less compressed, much stouter 
and thicker. Epidermis of a deep yellow brown, instead of waxen; shape 
more trigonal with posterior ventral margin more produced; umbones dark 
umber brown, ligament longer stouter and much more prominent; lunule 
almost obsolete, with waves continued over it instead of smooth. Concen¬ 
tric sculpture in waves, not separated by grooves as in L. fluctuosa, of the 
same size, but further apart, more irregular and rounded or sharp instead 
of flattened. Hinge line broader, teeth larger and much stouter than in 
any other species; pallial sinus shallower and rounder, and muscular 
impressions proportionately larger than in any other form of the genus. 
Long. 8; alt. 0.64; diameter, 0.36 inch. (Dali). 
Type in U. S. N. M. Type locality, Port Simpson, British Columbia. 
Range. Known only from the type locality. 
Liocyma viridis Dali, 1871. 
Plate 1, fig. 3. 
Amcr. Jour. Conch., 7:146; pi. 14, fig. 8. 
Shell of a beautiful pea-green, covered with a beautifully polished 
epidermis; sculpture of very fine rather sharp concentric waves, very 
regular in outline. Epidermis between the waves raised in minute bubble¬ 
like globules. Numerous faint rather distant impressed lines, not striae or 
grooves, radiating from the umbones, which are rather small and acute. 
Shell thin but not compressed, waves flattened. Hinge line very narrow, 
teeth slender but distinct, very close together. Umbones in the anterior 
third. Ventral margin produced and greatly arched. Anterior end rather 
pointed, short. Pallial sinus small, sharply angulated. Muscular scars 
small. Hinge line very slightly arched. Length, 1; height, 0.66; diameter, 
0.35 inch. (Dali.) 
Type in U. S. N. M. Type locality, Arctic Ocean. 
Range. Arctic Sea southward to Japan and east to Kodiak Island, 
Alaska. 
Genus VENERUPIS Lamarck, 1818. 
Shell elongated, moderately tumid, surface rugosely striated and ribbed, 
distinctly gaping posteriorly; hinge in the right valve with two cardinal 
teeth, and a third very small, but usually obsolete, anterior; the middle 
one is prominent, curved as in Petricola; the posterior is longitudinally 
lamellar, low and bifurcate; in the left valve are three distant and very 
unequal cardinal teeth; the middle one is similarly projecting as the corre¬ 
sponding tooth in the other valve. (Tryon. S. S. Conch.) 
