dorsal margin and finer sculpture . 



1-here is a possibility that this is the form v/hich Crup-ny 

 designated pemisylvani oum ; the uneommon occurrence, hc-ever, 

 militates againt the supposition. Here, as elsewhere in the r^roper 

 placing- of Guppy's erroneoiTSly determined S;-)ecies, Dall ' s state- 

 ments are followed since he had access to original labels in 

 Guppy's collection. 



This S'^ecies is named for Dr. Amos ?. Brown, of the Univer- 

 sity of Peniiaylva-ciia, v/ho has made several cont:.'ibutioxio bo the 

 paleontology of tropical Am.erica. 



Occurrence .- lower 1.1 ioc ene : ''owden bed^i, _^ov;den, Jamaica. 



