216 MELANIID^. 



var. 



1 Brazil ; ex c. Prof. W. Newcomb. 

 Resembles M. Brot's pi. 39, fig. 12 c. 



Genus DORYSSA, H. Sf A. Adams. 

 Gen, Moll. I, p. 304, 1856, type M. atra, Richard. 



1. Doryssa transversa [?]. 

 Melania transversa, Lea, Zool. 1850, Guiana. 



var. subdevians, nov. [? D. subdevians, n. sp.]. 



3 Amazons; ex c. Prof. W. Newcomb [labelled " Mel. transversa, Rv."~\. 

 Long. 26, diam. 12| mil. 



Strongly decollate, three or four whorls only remaining. 

 Dark-brown colour, not light as M. Brot says Reeve's species 

 always is. Longitudinal sculpture obsolete on the last whorl. 

 But for its much larger size, M. Brot's pi. 35, fig. 10 A. [D. 

 devians] well represents the form. 



2. Doryssa consolidata. 



Bulimus consolidates, Bruguiere, JSnc.Meth., 1790 ; fide Brot=H. decollata, 

 Gmelin=Mel. circumsulcata, Busch, 1858 = Mel. scarabus, Reeve. 



3 "Tocantines River," Brazil; ex c. Prof. W. Newcomb [labelled " Mel. 

 scarabus, Rv."]. 



Last whorl less convex than in M. Brot's figure ; it is also less 

 decollate, four whorls remaining. 



3. Doryssa aquatilis. 



Melania aquatilis, Reeve, Icon., 1859, Rio Branca, Guiana ; fide Reeve 

 [w "errata""] and Brot =Mel. branca, Rv., 1860, from Rio Branca. 



1 South America ; ex c. G. Nevill, Esq. 



4. Doryssa subimbricata. 



M elania subimbricata, Philippi, Abb. Ill, 1851, Hab. ? [not Faunus subim- 

 brvcatus of Brof]. 



C Brazil; ex c. Prof. W. Newcomb [labelled "M. subimbricata, Ph."]. 



