470 



American Se ash ells 



compressed. Beaks tiny, quite near the rounded anterior end. Right valve 

 smoothish and transkicent cream. Left valve more prominently divided into 

 2 portions by a slight radial groove, anterior to which the shell is dull cream, 

 and posterior to which the shell is more glossy but with microscopic con- 

 centric growth lines. Sometimes slightly iridescent. Interior pearly. Mod- 

 erately common in sand below low water to 60 fathoms. 



Pandora arenas a Conrad, the Sand Pandora, (Carolinas to southeast 

 Florida) is commonly dredged by amateurs. It is very much like trilineata, 

 but never over /^ inch in length, completely lacking the rostrum and with 

 a quite convex left valve which has an external radial rib below the hinge 

 margin ridge. Common. P. carolinensis Bush is this species. 



Figure 96. Atlantic Pandoras, a, Pandora bushiana Dall, 1^ inch (Florida); b, 

 P. trilineata Say, % inch (Atlantic Coast); c, P. gouldiana Dall, i inch (northern 



Atlantic Coast). 



Gould's Pandora 



Figure 96c 



Pandora gouldiana Dall 



Gulf of St. Lawrence to Cape May, New Jersey. 



% to I % inches in length, similar to trilineata, but less elongate with the 

 height slightly more than half the length. The posterior rostrum on the hinge 

 line is very short, stubby and turned up. The shell is opaque, chalky and 

 commonly worn away, showing the pearly underlayers. Margin of valves 

 bordered with blackish brown periostracum. Common from intertidal areas 

 to 20 fathoms. 



Subgenus . Kennerlia Carpenter 1864 

 Pandora filosa Carpenter Western Pandora 



Alaska to Ensenada, Lower California. 



