)7 - 



He narks ,- -his characteristic species, which -as an extend- 

 ed geologicsl rarg-e in the Antillean region and its perimeters, is 

 well rei^resented in the 3c!?-.'den fauna. The shape, and the peculiar 

 half-imbricated and reticulated character of the seixlpturing alone 

 se nre to distinguish this species from the other memhers of the 

 genus. 



Occurrence .- Upper Eocene.- Jackson group, Jackson, Miss- 

 issippi (Dall, 1398). Oligocene.- Tampa silex beds, Tampa, Flo- 

 rida (Ball, 1898, 1915). Ghipola marl, Florida (Dall, 1898), 

 Katura, Trinidad (Guppy, 1874, "Pliocene"; Dall, 1898). i^^er 

 Miocene: Bowden beds, BCT^-den, Jamaica. (Dall, 1G98). Pliocene. - 

 limon, 3osta ?.ica (Dall, 1898). Oaloosahatchie marl, Florida 

 (Dall, 1898)j^ ?lei£t02e.:e.- Antilles generally (Dall, 1898). 

 Recent.- Hatter as to Gulf of Oarapeche and east to Bermuda in o to 

 287 ■?. Occurs in both deep and shallow -.vater off Hatteras; else- 

 where in shallov; v/ater onlv. 



