
MARINE AQUARIA 

found on the sandy beaches on the Atlantic coast from Labrador to Cape 
Hatteras. 
Petricola pholadiformis, (Lam.), or Boring Clam, has elongated, acutely 
rounded, chalky, 1% inches long valves, the anterior part short and the 
posterior long and neatly rounded. The animal has two long siphon 
tubes united at the base, with the inhaling tube the longer. Found in 
varying localities along the Atlantic coast at low-water marks. 
Acra transversa, (Say), or Common Cockle, has rhomboidal, oblong 
11% inches long valves, with 32 to 35 ridges or ribs placed in radiating lines 
from the umbones to the margins. This is the common radiate-shelled 
clam of the Atlantic coast. 
Venus mercinaria, (Linn.), or Common Hard-shell Clam, Quahog, 
has thick and solid, obliquely ovate or heart-shaped grey and chalky valves 
with the anterior ends very short, the posterior ends terminating in a blunt 
truncated point, and the curved and elevated umbones placed far forward 
_to project nearly to the front of the shell. This clam is brought into the 
market under different names, the younger as the Cherry Stone and Little- 
neck, the older as the Hardshell, and the very large ones, which reach a 
length of 3% to 4 inches, as the Chowder Clam. Those having shells 6 
inches long or larger are known as Horse or Sea Clams. Common along 
the entire Eastern and Middle States Coast. 
Mytilus edulis (Linn.), or Edible Mussel, has thin, polished, triangu- 
lar-ovate, dark-bluish, 2% inches long valves, with a pointed beak and 
plainly defined lines of growth. The umbones are immediately at the 
beak. Very common between tide-marks on the Atlantic coast, from the 
Arctics to North Carolina. 
Modiolus plicatulus, (Lam.), or Horse Mussel, has oblong-ovate 
much elongated greenish-brown and horn-colored 2 to 3 inches long 
valves ; with the posterior end traversed by numerous radiating ribs. The 
umbones are placed above the beak. Common on muddy banks of estu- 
aries and shores, crowded in vast numbers, exposed at low tide; from 
Nova Scotia to Georgia. 
Pecten gibbus, var. irradians, (am.), or Common Scallop, has nearly 
round, rather strong, dusky or blackish 21% inches long valves, having 
about 20 elevated, rounded ribs, wrinkled concentrically by fine lines of 
growth, and an ear-like hinge about two-thirds as broad as the shell. 
Common along almost the entire Atlantic coast from Nova Scotia to 
Tampa, Fla. 
Ostria virginica, (Gmel.), or Chesapeake Bay Oyster, has now be- 
come a widely distributed native species, found along the entire Atlantic 
coast. Owing to its sedentary life, it has become very irregular in both 
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