log BUI.I.KTIN 38 139 



Distribution. — Gun Ca}^, East Fla., 498 fms., Yucatan 

 Strait at 640 fms. 



acuticostata Dall, Bull. M. C. Z., 18, p. 2S0, pi. 19, f. 10, 1889; 

 Bull. 37, U. S. N. M., p. 150, pi. 19. f. 10, '89. 



Distribution. — Yucatan Strait, 640 fms., and between Mis- 

 sissippi delta and Cedar Ke3^s, 32 fms. Also off Hatteras 

 and Barbados. Probably a variety of R, xanthias Watson 

 (Chall Gastr., p. 588, pi. 44, f. 5, 1885). 



Genus RISSOll^A d'Orbigny 



decussata Montagu, Test. Brit., p. 399, 1803, (as Turbo)-, 

 Schwartz von Mohrenstern, Denkschr. d. Kais. Akad. d. 

 Wissensch. Wien. 19, p. 80, f. 12, i860; Trj'On, Man., 9, p. 

 385, pi. 58, f. 15, 1887; E>all, Bull. M. C. Z.. 18, p. 281, 

 '89; Tr. W. I. S., 3, p. 343, '92. 



Distribution. — Cape Fear, N. C, to Haiti and to West Fla. 

 2-17 fms. Also European. Variety planata Dall, Caloosa- 

 hatchie Pliocene. 



laevigata C. B. Adams, Contr. Conch., p. 114, 1850; Schwartz 

 von Mohrenstern, Denk. Kais. Ak. Wien., 19, p. iii, f. 79, 

 i860; Tryon, Man., 9, p. 390, pi. 59, f. 48, '87; Dall, Tr. 

 W. I. S., 3, p. 342, '92. 



Distribution. — Cape Lookout, N. C, to St. Thomas, W. I. 

 Also West Florida. 0-22 fms. Pliocene, Caloosahatchie 

 beds. Eower Miocene, Chipola beds, West Fla. 



chesnefi Michaud, Descr. des Coq. Nouv., p. 17, 1832, (as Ris- 

 soa)\ Tryon, Man., 9, p. 380, pi. 56, f. 73, '87; Dall, Tr. 

 W. I. S., 3, p. 343, '92; Singley, 4th Ann. Rept. Tex., p. 

 341, '92. 



Distribution.^ — Hatteras to Guadeloupe, Gulf coast: Cedar 

 Keys, Fla.; Corpus Christi, Tex. Also Mediterranean and 

 Mauritius. Pliocene, Caloosahatchie beds, West Fla. 



browniana d'Orbigny, Moll, Cuba, 2, p. 28, pi. 12, f. 33, 35, '42; 



