OF THE UNITED STATES. 26l 



reddish, almost obsolete spots, on the margin, at the 

 base of the auricles ; auricles subequal ; hinge mar- 

 gin rectilinear in each valve. 



Length one inch and a half. 



Breadth one inch and three-fifths. 



My Cabinet. 



This is a very pretty species, and seems to be con- 

 fined to the southern coast, where it is rare. It is 

 very different in its coloured markings from the pre- 

 ceding species, which, however, it much resembles in 

 form. I have a young specimen, on which the red 

 lines are numerous, but are dilated; pale, and tinted 

 with dull purplish. 



PANDORA, Brug. 



Species. 



P. *trilineata. Shell white, subpellucid, concen- 

 trically wrinkled; hinge placed at the posterior slope, 

 which is very abrupt, and forming a very considerably 

 obtuse angle with the hinge margin ; hinge margin 

 concavely much arquated, the surface flattened, and 

 bounded on its edges by two elevated approximate 

 lines, originating at the beak and continued to the 

 tip, which is rostrated ; rostrum ascending ; a distinct 

 slightly impressed line originates at the beaks, and 

 passes to the middle of the basal margin 5 right valve 

 a little convex ; left valve flat. 



Length nine-twentieths of an inch. 



Greatest breadth nineteen-twentieths of an inch. 



