64 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 50 



name Cactus will be explained in full in a more extensive paper 

 on the Cactaceae to be published later. It is well known that the 

 late Otto TCuntze not only referred Melocactus to Cactus but also 

 Mamillaria and even Cereus, Echinocactus, and similar genera. The 

 present use of the name Cactus is not to be understood as countenanc- 

 ing this wholesale reduction of genera, which in my view has no 

 justification whatsoever. 



