78 MOI.I.USCA OF THK Gulf of Mexico 48 



'89; Singley, 4th Ann. Rept. Tex., p. 333, '92; Vanatta^ 

 Pr. A. N. S. Phila., 55, p. 757, 1903; Vaughan, 2nd Ann. 

 Rept. Fla. Geol. Surv., p. 148, 1909. 



covoidalis Reeve, Conch, Icon., 15, pi. 18, f. 87. 



Distribution. — Hatteras to Jamaica, Gulf coast: West Fla. 

 and Texas, Pleistocene, Manatee, Orient and Labelle, West 

 Florida. 



pellucida Pfeiifer, Wiegmann's Arcbiv; i, p. 258, 1840; Tryon, 

 Man., 5, p. 33, pi. 10, f. 91, '83; Dail, Bull. 37, U. S. N. 

 M., p. 106, '89. 



Distribution. — Sarasota, West Fla. and West Indies. 



watsoni Dali, Bull. M. C. Z., 9, p, 71, 1881; 18, p. 137, pi. 19, f. 

 3, pi. 38, f. 2, '89; Bull. 37, U. S. N. M., p. 106, pi. 19, f. 

 3, pi. 38, f. 2, '89. 



Distribution. — Yucatan Strait, 640 fms. Also off Havana, 

 220-805 fms. 



virginiana Conrad, Am. Jour, Conch., 4, p. 67, pi. 5, f. 4, 1868, 

 (as Prunum); Dall, Bull. 37, U. S. N. M., p. 106, '89; Tr. 

 W. I. S., 3, p. 48, '90. 



Distribution. — Recent, North Carolina to Yucatan, 10-294 

 fms. Pliocene, Caloosahatchie beds, Fla. Miocene, James 

 River, Va. 



denticulata Conrad, Jour. A. N. S. Phila., 6, p. 225, pi. 9, f. 21, 

 1830. (Not of Tate, '78); Dall, Bull. 37, U. S. N. M., p. 

 108, '89; Tr. W. 1. S. 3, p. 51, Pl. 5 f. 8, 1890. 



Distribution. — Recent, Hatteras to Barbados. Also West 

 Florida, 5-294 fms. Pliocene, Caloosahatchie beds, Upper 

 Miocene, Maryland and Virginia. 



opalina Stearns, Pr. Bost. Soc. N. H., 15, p. 21, 1872; Dall, Pr. 

 U. S. N. M., 6, p. 324, '83; Bull. 37, p. 108, '89, (as den- 

 ticulata var. opalina^. 



Distribution. — Hatteras to Barbados. Recent, Tampa (type 



