interesting species are fast disapiicarino- and some of them have already become 

 extinct: he needs only mention tlic magnificent species of Cyanea arborca, 

 C. Giff'ardii. ('. supcrba and others; and if the publication of this paper should, 

 besides gi\'ing- a full and explicit account of every known species, be the means 

 of arousing interest in the preservation of these rare and curious plants, the 

 writer's aims will indeed have b(>en attained. 



Joseph F. Rock. 

 Ilouohilu, May 17, I'JIS. 



