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436 A?rierican Seashells
2 to 3 inches in length, equally high. Characterized by its heavy shell,
by the coarse, wide, irregular, concentric folds on the outside (resembling
rotting bark or wood). Exterior yellowish gray; interior glossy-white, with
a purple tinge, especially prominent on the hinge and margins. Commonly
found in rocky rubble in shallow water.
Genus Ciimingia Sowerby 1833
Shell delicate, with concentric lamellae; slightly gaping behind. Resilium
internal and supported by a spoon-shaped chondrophore. One cardinal and
2 elongate lateral teeth in each valve.
Cumingia telUnoides Conrad Tellin-like Cumingia
Nova Scotia to St. Augustine, Florida.
% to % inch in length, oblong and fairly thin. Slightly pointed at the
posterior end. Exterior chalky-white, with tiny, sharp, concentric lines. This
is a moderately common mud-digger which externally resembles a Tellina.
The subspecies va?ihy?jhigi Rehder 1939 replaces the typical species in
southern Florida to Texas. It is not so high, is more elongate and more
drawn out posteriorly. Common in shallow water. C. coarctata Sowerby
(Lower Keys and West Indies) has stronger, more widely separated con-
centric ridges.
Cumingia calijornica Conrad Californian Cumingia
Crescent City, California, to Chile.
Plate 31
I to 1% inches in length, elongate-oval, moderately compressed. In
front of the beaks there is a small, elongate depression. Just posterior to and
partially covered by the inroUed beaks is a small, short ligament, posterior to
which is a wide, flaring furrow. Concentric sculpture of numerous wavy,
rather sharp, fairly large threads. Color grayish white. Pallial sinus very
long. Abundant in rock crevices and wharf pilings. Also dredged down to
25 fathoms.
Genus Abra Lamarck 18 18
Shell small (/4 inch), fragile, ovalish, smooth, moderately compressed.
Translucent-white in color. Resilium internal and supported by a linear
chondrophore. Right valve with 2 cardinals and generally with 2 lamellar
laterals.
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