MARYLAND GEOLOGICAL SURVEY 197 



Description. — " Linear, straight, except towards the summit, where 

 it is slightly recurved, gradually widening from the hinge downwards; 

 basal margin rounded, slightly towards the posterior extremity; anterior, 

 margin obliquely truncated, not reflected; cardinal teeth, one in the 

 right valve, compressed, in the opposite valve two, the superior one very 

 small and near the extremity, the other somewhat distant, elevated, ro- 

 bust, slightly recurved. Length, four inches." Conrad, 1843. 



Fragments only of this species have been found. It is rare in the 

 Maryland Pleistocene and. is distinct from the smaller southern form 

 known as E. minor Dall. 



Its earliest occurrence is in the Oligocene of Florida. In the Miocene 

 it has been found at numerous localities from Maryland to Florida. It 

 occurs in the Pliocene of the Carolinas and Florida, in the Pleistocene it 

 ranges from Maine to Maryland and in the Eecent from Labrador to 

 Florida. 



Length, 123 mm. ; height, 23 mm. 



Occurrence. — Talbot Formation. Wailes Bluff near Cornfield Har- 

 bor, St. Mary's County. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 and U. S. National Museum. 



Superfamily TELLINACEA. 

 Family SEMELIDAE. 



Genus CUMINGIA Sowerby. 



Cumingia tellinoides (Conrad). 



Plate LVI, Figs. 1, 2, 4, 5. 



Mactra tellinoides Conrad, 1831, Jour. Acad. Nat. Sci. Phila., vol. vi, 1st ser., 



p. 258, pi. xi, figs. 2, 3. 

 Cumingia tellinoides Holmes, 1858, Post-Pi. Fos. S. C, p. 53, pi. viii, fig. 12. 

 Cumingia tellinoides Dall, 1889, Bull. U. S. Nat. Mus., No. 37, p. 62, pi. Ivi, 



fig. 14. 

 Cumingia tellinoides Dall, 1900, Trans. Wagner Free Inst. Sci., vol. iii, . pt. 



v, p. 1000. 



