436 A?rierican Seas hells 



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 



Plate 31 V 



Crescent City, California, to Chile. 



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. 



