198 SYSTEMATIC PALEONTOLOGY 



Description. — " Shell ovate, thin, fragile, with numerous raised, con- 

 centric striae, one end regularly rounded, the other slightly compressed 

 and somewhat pointed at the extremity; lateral teeth distinct in one 

 valve, in the other obsolete." Conrad, 1831. 



This beautiful little species has often been confounded with C. medialis, 

 a common Miocene species of Virginia and the Carolinas. The latter, 

 according to Dall, is distinguished by its " larger size, more conspicuous 

 socket for the recilium, less elongation and less prominent surface sculp- 

 ture." 



This species is known in the Pleistocene from Massachusetts, Mary- 

 land, and South Carolina, and in the Eecent ranges from Prince Edward 

 Island to Florida. 



Width, 17.5 mm.; height, 6.3 mm. 



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

 bor, St. Mary's County. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 and TJ. S. National Museum. 



Family TELLINIDAE. 



Genus TELLINA (Linne) Lamarck. 

 Subgenus ANGULUS Megerle. 



Tellina (Angelus) tenera Say. 

 Plate LVI, Figs. 3, 6. 



Tellina tenera Say, 1822, Jour. Acad. Nat. Sci. Phila., vol. ii, 1st ser., 



p. 303. 

 Tellina tenera Dall, 1889, Bull. U. S. Nat. Mus., No. 37, p. GO, pi. lv, fig. 1, 



pi. lvi, fig 13. 



Description. — "Shell very thing and fragile, pellucid, compressed, 

 transversely oblong-suboval, whitish, iridescent, concentrically wrinkled; 

 basal edge arquated, not rectilinear opposite to the beaks; hinge teetii 

 two, larger one emarginate; posterior tooth but little elevated: anterior 

 tooth obsolete; beak placed behind the middle." Say, 1882. 



