56 MOLIvUSCA OF THB Gui.F OF MEXICO 26 



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

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

 England coast. 



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



Auricula coryiea 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 flavus with which they may hybridize. Inhabits 

 Salt marshes. 



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

 4, 1803, (as Vohita); Dall, 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, {d.s Leuconia) ) Pr. U. S. N. M., 8, p. 286, pi. 18, f. 

 II, '85; Bull. U. S. N. M., 37, p. 92, pl. 47> f- '§9; 

 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, pl. 18, f. 10, 

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

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



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

 Corpus Christi, Texas and the Bahamas. 



Genus PLAWORBIS Guettard 

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



