MARYLAND GEOLOGICAL SURVEY 191 



chusetts to Florida, and in the Eecent from Prince Edward Island to 

 Florida and Trinidad and along the coast of the Gulf of Mexico to Texas. 



Width, 17 mm.; height, 30 mm. 



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

 bor, and Langleys Bluff, St. Mary's County. 



Collections. — Maryland Geological Survey, Johns Hopkins University 

 and U. S. National Museum. 



Family NATIC1DAE. 



Genus POLYNICES Monlfort. 



Subgenus NEVERITA Risso. 



Polynices (Neverita) duplicatus (Say) 

 Plate LI, Figs. 9, 10. 



Natica duplicate/, Say, 1822, Jour. Acad. Nat. Sci. Phila., vol. ii, 1st ser., 



p. 247. 

 Natica duplicata Holmes, 1859, Post-PL Fos. S. C, p. 80, pi. xii, fig. 14. 

 Natica (Neverita) duplicata Dall, 1889, Bull. U. S. Nat. Mus., No. 37, p. 152, 



pi. Ii, fig. 12. 

 Polynices (Neverita) duplicatus Dall, 1892, Trans. "Wagner Free Inst. Sci., 



vol. iii, pt. ii, p. 368. 

 Polynices (Neverita) duplicata Martin, 1904, Md. Geol. Survey, Miocene, 



p. 252, pi. Ix, fig. 1. 



Description. — " Shell thick, sub-globose, cinereous, with a black line 

 revolving on the spire above the suture, and becoming gradually diluted, 

 dilated and obsolete in its course; within brownish-livid; a large incras- 

 sated callous of the same color extends beyond the columella, and nearly 

 covers the umbilicus from above; umbilicus with a profound sulcus or 

 duplication." Say, 1822. 



The variability shown in this species has resulted in various synonyms, 

 as described by Dall in his monograph on the Tertiary fossils of Florida. 

 The earliest appearance of the species is in the Miocene where it ranges 

 from New Jersey to Florida. It is found in the Pliocene of the Caro- 

 linas and Florida and in the Pleistocene from Maryland, South Carolina, 



