56 MOLLUSCA OF THE GULF OF MEXICO 26 



Binney, Land & Fr. W. Sh., 2, p. 10, '65; Not bidentahis 

 Montagu, 1803, which is European, but introduced on New 

 England coast. 



biplicatus Pfeiffer, Mon. Auric. Viv., p. 21. 



Auricula cornea Deshayes, Ency. Me'th., 2, p. 90, 1830; 

 Jaumei Mittre', 1841. 



Distribution. — Maine to Tortola Isl., Gulf coast: Tampa, 

 Cedar Keys, St. Mark's, Fla.; Point au Fer. Chaudeleurs, 

 Belle Isle, La ; Galveston, Tex. 



Note. — Northern specimens very distinct; southern grade 

 towards y?a77<.y with which they may hybridize. Inhabits 

 salt marshes. 



(Detracia) bulloides Montagu, Testacea Brit., p. 339, pi. 30. f- 

 4, 1803, (as Voluta); Ball, Pr. U. S. N. M., 8, p. 285, pi. 

 18, f. 7, 1885; Bull. 37, U. S. N. M., p. 92, pi. 47, f. 7, '89. 



Distribution — Cedar Keys, Fla. and the Antilles. Type of 

 Gray's subgenus Detracia. 



(Sayella) hemphilli Dall, Pr. U. S. N. M., 6, p. 323, pi. 10, f. 6, 

 1883, {2.^ Leitconia); Pr. U. S. N. M., 8, p. 286, pi. 18, i. 

 II, '85; Bull. U. S. N. M., 37, p. 92, pi. 47, f. II, '89; 

 Singley, 4th Ann. Kept. Tex. Surv. p. 343, '92. 



Distribution. — Cedar Keys, Florida, and Corpus Christi, 

 Texas. Type of section Sayella Dall which is intermediate 

 between Blauneria and Detracia. 



(Sayella) crosseana Dall, Pr. U. S. N. M., 8, p., 286, pi. 18, f. 10, 

 '85; Bull. 37, U. S. N. M., p. 92, pi. 47, f. 10. '89; Singley, 

 4th Ann. Rept. Tex. Surv., p. 343, '92. 



Distribution. — West Florida at Egmont Key (Tampa Bay); 

 Corpus Christi, Texas and the Bahamas. 



Genus PLAN0RB1S Guettard 

 ophis Dall, Proc. U. S. N. M., 46, p. 236, 'pi. 21, f. 3, 4, 1914. 



