144 MOLLUSCA OF THE GULF OF MEXICO II4 



Borgne borings, New Orleans well of 1856, and New Orleans 

 pumping station No. 7. Pliocene, Caloosahatchie beds. 

 Lower Miocene Chipola beds, West Fla. 



plana Say, Jour. A. N. vS. Phila., (i), 2, p. 226, 1822; Tuoraey 

 and Holmes, PI. Foss. S. Car., p. iii, pi. 25, f. 12, 1857; 

 Ball, Bull., 37, U. S. N. M., p. 152, pi. 48, f. 12, pl. 50, f. 

 26, '89; Tr. W. I. S., 3. p. 358, '92: Vanatta, Pr, A. N. S. 

 Phila., 55, p. 75!*, 1903; Johnson, Occ. Pa.Bost. Soc. N. H., 

 7, p. no, 1915. 



Distribution. — Canada to Trinidad, W. I. Gulf coast: Cedar 

 Keys, St. Mark's, Fla.; Chandeleurs,La. ; Galveston, Corpus 

 Christi and Matagorda Baj^s, Texas. Pleistocene, New Or- 

 leans pumping station No. 7 and North Creek, Fla. 

 Pliocene, New Orleans Gymnasium Club well at 1 200 feet, 

 and Caloosahatchie beds, Fla. Low^er Miocene Chipola beds. 

 West Fla. and of the Bascom No. i well, Mobile, Ala., at 

 1 500- 1 556 feet, Chipola horizon. 



acuieata Gmelin, Syst. Nat., 7, p. 3693, 1792, {Patella); Tryon, 

 Man., 8, p. 129, pl. 39, f. 61-62, 18S6; Ball, Bull. M. C. Z., 

 18, p. 286, 1889; Vanatta, Pr. A. N. S. Phila., 55, p. 758, 

 1903: Ball. Bull. 112, U. S. N. M., p. 162, 1921. 



Bistribution. — Cape Lookout, N. C, to Barbados. Gulf 

 coast: Indian Pass, West Fla., and Texas. Usually 0-25 

 fms. , but dredged in Gulf of Mexico, near Tortugas at 539 

 fms. Bwarfed and white at that depth. Also Pacific Ocean, 

 California to Chile. Pliocene, Caloosahatchie beds, West 

 Florida. 



convexa Say, Jour. A. N. 8. Phila., (i), 2, p. 227, 1822; Ball, 

 Bull. 37, U. S. N. M., p. 152, pl. 50, f. 25, 1889; Tr. W. 

 I- S., 3, p. 357, '92. 



Bistribution. — Nova Scotia to Florida. Gulf coast: West 

 Fla.; Chandeleurs, La.; Galveston, Tex. Pleistocene, North 

 Creek, West Fla. 



