MARYLAND GEOLOGICAL SURVEY 207 



of the hinge margin; extremities of the hinge margin angulated; an- 

 terior edge, superior moiety rectilinear; posterior edge rounded; inferior 

 edge nearly rectilinear, or very obtusely rounded; on the hinge space one 

 or two angulated lines are drawn from the apex, diverging to the hinge 

 line." Say, 1822. 



This common form is first known from the Pliocene of Florida. In 

 the Pleistocene it ranges from Massachusetts to Florida, and in the Be- 

 cent from Cape Cod south to Florida and west to Mexico. 



Width, 21.5 mm.; height, 8 mm. 



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

 bor, St. Mary's County; Federalsburg, Caroline County. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 and TJ. S. National Museum. 



Superfamily NUCULACEA. 

 Family NUCULIDAE. 



Genus NUCULA Lamarck. 

 Nucula proxima Say. 

 Plate LXV, Figs. 1-4. 



Nucula obliqua Say, 1820, Amer. Jour. Sci., vol. ii, p. 40; not of Lamarck 



1819. 

 Nucula proxima Say, 1822, Jour. Acad. Nat. Sci. Phila., vol. ii, 1st ser., 



p. 270. 

 Nucula proxima Holmes, 1858, Post-Pi. Fos. S. C, p. 17, pi. 3, fig. 6. 

 Nucula proxima Dall, 1889, Bull. U. S. Nat. Mus., No. 37, p. 42, pi. xvi, fig. 4. 

 Nucula proxima Dall, 1898, Trans. Wagner Free Inst. Sci., vol. iii, pt. 4, 



p. 574. 



Description. — " Valves obliquely sub-triangular, obsoletely striate 

 transversely, one or two of the stria? more conspicuous ; numerous, hardly 

 perceptible longitudinal strise; anterior and posterior lines form- 

 ing an acute angle; umbo obtuse; apex acute; teeth angulated, promi- 

 nent, cavity at the apex of the hinge profound, rather long; basal mar- 

 gin denticulatocrenate. Greatest length one-fifth of an inch/' Say, 

 1820. 



Dall mentions the fact that Say's type was obtained from the southern 



