THE ROCKY MOUNTAIN SPOTTED-FEVER TICK. 167 
development. It seems very probable, in the light of our recent 
investigation, that this note applies to the rabbit tick, Haemaphysalis 
leporis-palustris. Additional information on the host relationships of 
this species is given by Hunter and Bishopp (1911b). 
Fic. 14.—The Rocky Mountain spotted-fever tick, Dermacentor venustus: Distribution in the United 
States. The large dots show localities where the species has been collected in our investigation. The 
small dots indicate the probable range of the tick. (Original.) 
We have been able to engorge all the stages of the Rocky Mountain 
spotted-fever tick on the guinea pig, tame rabbit, and bovine, and 
the adults have been engorged on the goat. 
