FAMILY VENERIDZ — VENUS. 217 
GENUS VENUS. Linnaeus. 
Animal oval, moderately thick, with the edges of the mantle undulated, and furnished with 
a row of tentacular cirri. ‘Tubes rarely separated. Mouth small, with the labial appen- 
dages small. Foot occasionally semilunar, not furrowed beneath. Shell solid, inequilateral, 
subovate ; hinge with three diverging cardinal teeth in each valve; ligament external ; 
cordiform depressions beneath the beaks: palleal impression with a sinus. - 
VENUS MERCENARIA. 
PLATE XXVIII. FIG. 276. 
(STATE COLLECTION.) 
Venus mercenaria, Ln. Syst. Nat. 1131. Russet, Ess. Jour. Nat. Hist. Vol. 1, p. 58. 
Ve id. Lam. ubi supra, Vol. 2, p.610. Gounp, Invertebrata of Mass. p. 85, fig. 67. 
Description. Shell large, solid and ponderous, inequilateral, subcordate ; beaks incurved, 
and projecting forwards and inwards. Anterior area heart-shaped, and bounded by an 
impressed line. Surface, in the old shells, with numerous coarse grooves and ridges ; in the 
young, with concentric lamellar ridges. Epidermis very slight, and easily detached : ligament 
stout and prominent ; posterior area obsoletely plicate. Basal margin entire, but crenulated 
within ; anterior margin rounded ; the posterior more pointed. In the one valve, the anterior 
tooth is largest and distant from the other two, which are oblique and contiguous ; in the 
other valve, the two anterior teeth are united, forming a simple bifid tooth: this is most 
striking in aged individuals. ‘The remainder of the hinge is composed of roughened irregular 
points, interlocking with those of the opposite valve. Muscular impressions deep, and united 
by the palleal impression, which has an angular sinus near the posterior impression. 
Color. Externally varying from brownish white to ash-grey, and, in very old specimens, 
with a rufous tinge, frequently deep blackish brown; but the color appears to vary with the 
bottom upon which they live. Within, white, with a deep violet or purple margin. 
Vertical axis, 2°0 — 3°5; transverse ditto, 3°0 —4°5. Diameter, 1-8 — 2°3. 
This species is the common Round Clam, much prized as an article of food, and so savory 
in some localities as to be equally valued with the Oyster. Its aboriginal name of Quahog 
has now fallen into disuse. It sells in the markets at prices varying from thirty-seven and a 
half to sixty-two and a half cents the bushel. It abounds in all our bays, a few inches beneath 
the bottom, from low-water mark to two or six fathom water. If taken from its bed and placed 
on its side, it can, in the course of a single tide, bury itself six inches beneath the surface. 
From the internal purple part of the shell, the colored beads of the aborigines were formerly 
manufactured, constituting the seawan or wampum, the specie currency of the natives. Long 
island was formerly the great mint for the supply of this article, and hence its Mohegan 
Fauna — Part 6. 28 
