I05 BULIvBTTN 38 , 135 



Distribution. — Hatteras to Grenada Isl. Gulf of Mexico, 

 West of Florida, at 14-50 fms. , and the coast of Texas, Vera 

 Cruz and Yucatan. 3-413 fms. The Pliocene, closely relat- 

 ed form is T. subanmdata Heilprin of the Caloosahatchie 

 marl. 



chipoiana Dall, Trans. Wagner Inst. Sci., 3, p. 312, pL 22, f. 24, 



Distribution. — Lower Miocene of the Chipola beds. West 

 Florida, and of the Bascom No. 2 well. Mobile, Ala., at 

 124 1 feet, Chipola horizon. Aldrich's collection. 



subgrundifera Dall, Trans. Wagner Inst. Sci., 3. p. 313, pi. 22, f. 

 23, 1892. 



Distribution. — I^ower Miocene, Chipola beds, Calhoun Co., 

 West Fla., and of the Bascom No. 2 well, Mobile, Ala., at 

 1 24 1 feet, Aldrich's collection. A varietal form was record- 

 ed by Harris from the Upper Miocene, Galveston well, at 

 2552-2920 feet. 



terebriformis Conrad, Cat. Mio. Foss., Pr. A. N. S. Phila., p. 

 568, 1863, (Name only); Dall, Tr. W. I. S., 3, p. 311, 

 1892. 



Distribution. — Lower Miocene, Chipola marl, Fla., and of 

 the Bascon No. i well, Mobile, Ala., at 1500- 1556 feet. 

 Aldrich's collection. Also Chesapeake Miocene of Easton, 

 Md. (Conrad's type locality). 



satilla Dall, Proc. U. S. N. M., p. 233, pi. 22, f. 6, 1914. 



Distribution. — Upper Miocene or Pliocene.. Well near Al- 

 exandria, La., at 49 feet. Brackish water formation. 



Genus IVIATHJLDA Semper 



yucatecana Dall, Bull, M. C. Z., 9, p. 90, 1881, (as Bittium); 18, 

 p. 266, pi. 20, f. 7, '89; Bull. 37, U. S. N. M., pi. 20, f. 



7. '89- 



Distribution. — -Gulf of Mexico, Yucatan Strait, 640 fms. 



