56 MOLLUSCA OF THE GULF OF MEXICO 26 



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

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

 England coast. 



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



Auricula cor7iea Deshayes, Ency. Me'th., 2, p. 90, 1830; 

 jauinei 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 

 lo^zx&s flavus with which they may hj^bridize. Inhabits 

 salt marshes. 



(Detracia) buUoides Montagu, Testacea Brit., p. 339, pi. zo^i. 

 4, 1803, (as Valuta)- 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) hemphiili Dall, Pr. U. S. N. M., 6, p. 323, pi. 10, f. 6, 

 1883, {?iS Leuconia) ; Pr. U. S. N. M., 8, p. 286, pi. 18, f. 

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

 Singley, 4th Ann. Rept. 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. 



