ISO MITRINiE. 



Sub-gen. swAINso^'IA, H. and A. Adams (Mitrella, Swains., 



not Risso). 



Shell oliviform, smooth, polished, sometimes covered with an 

 epidermis, last whorl anteriorly obtuse, expanded; spire nearly 

 or quite equal to the aperture ; columella with a few oblique 

 plaits ; outer lip smooth internally. 



bicolor, Swains. Isevis, A. Adams. 



casta. Swains. Mariae, A. Adams. 



filum, Wood. ocellata, Stvains. 



fissurata, Lam. zephyra, Recluz. 



fusca, Sivains. zonata, Marry att. 

 incisa, Adams and Reeve. 



Genus IMBRICARIA, Schumacher. 



Shell coniform, often covered with an epidermis; spire 

 depressed, apex mucronate ; aperture linear; columella 

 straight, with numerous transverse imbricate plates in the 

 middle ; outer lip thickened and sometimes crenulate. 



Syn. Conohelix, Sicains. 



Ex. I. olivaeformis, Siaainson, pi. 19, fig. 6. Shell, 

 1. conus, Chemnitz, fig. 6, a. . 



The species of this genus have much the same habits 

 as those of Cylindra, being found chiefly in sandy spots 

 among coral reefs; those with an epidermis, as /. conns, 

 have been found buried in black mud in Mangrove 

 swamps by one of the authors. 



Species of Imbricana. 



bacillum, ham. citrina. Reeve. 



carbonaria, Hinds. couica, Schum. 



