358 SYSTEMATIC PALEONTOLOGY 



Description. — " Shell perlaceous, concentrically wrinkled ; the large 

 valve extending much heyond the posterior base of the lesser; anterior 

 side very short, margin widely subtruncate; posterior obtusely rounded 

 inferiorly, terminating above in a very short and obtuse rostrum; dorsal 

 submargin of the larger valve with two approximate carinas ; lesser valve 

 witli only one distinct carina placed very near the margin; anterior car- 

 dinal tooth of the larger valve very long, thick, and slightly oblique, the 

 posterior one very near the dorsal line, sulcate or f osset shaped ; the middle 

 one sliort and linear; in the flat valve, two oblique, very thick and promi- 

 nent teeth, anterior to Avhich is a shallow groove, bounded anteriorly by a 

 rudimentary linear tooth; muscular impressions impressed; pallial im- 

 pression punctate." Conrad, 1838. 



Length, 20 mm.; height, 15 mm.; diameter, 4 mm. 



Occurrence. — St. Mary's Formation. Cove Point, St. Mary's Kiver. 



Colleciion. — Maryland Geological Survey. 



Subgenus KENNERLEYIA Carpenter. 



Pandora (Kennerleyia) lata Dall. 

 Plate XCV, Fig. 7. 



Pandora (Kennerleyia) lata Dall, 1903, Trans. Wagner Free Inst. Sci., vol. ill, pt. vi, 

 p. 1530, pi. Ivii, fig. 18. 



Description. — " Shell small, left valve very convex, patulous below 

 behind, with a rather broad escutcheon bounded by a strong carina; 

 anterior area short, posterior area very narrow; rostrum very short and 

 blunt, slightly recurved; surface concentrically striated; hinge-teeth 

 short and small; lunule very deep, compressed, so as to appear linear; 

 right valve slightly concave, concentrically striated, with traces of the 

 usual impressed radiating lines. Length 19.0, height 10.5, diameter 

 3.5 mm. 



This species is shorter and thicker than P. arenosa and much less 

 acute. Its exact provenance is not known, as it was received from the 

 old National Institute, but the specimens have the livid purple color 

 characteristic of many of the St. Mary's fossils, and it is possible it was 

 collected in that region." Dall, 1903. 



Occurrence. — St. Mary's Formation (?). St. Mary's County (?), 



Collection. — U. S. National Museum. (National Institute Collec- 

 tion). 



