344 



The Ixodidae are divided into two sub-families — 



1. RhipicephaUnae. — Palpi not longer than 



broad, rostrum short. Anterior portion 

 of body emarginate to receive the 

 rostrum. 



2. Ixodinae. — Palpi longer than broad, ros- 



trum long. Anterior portion of body 



straight or emarginate. 

 The RhipicephaUnae are the most important 

 from our standpoint, as to the genus Rhipicephalus 

 belong most of the ticks that are known to trans- 

 mit parasites. The various genera are Rhipice- 

 phalus, [Boophilus], Haemaphysalis, and Derma- 

 centor. 



Fig. 78. Tick under surface, shewing Anatomy and parts 

 used for classification. {Aftev Salmon and Stiles) 



Genus Rhipicephalus 



Eyes present. Base of rostrum hexagonal 

 (dorsally), forming on each side a projecting 

 angle. Palpi short and broad. Stigmata, comma- 

 shaped ; clypei, two pairs in the male. Coxae i, 

 two large teeth. The genus includes nearly thirty 

 species. Some of these, including the carriers of 

 piroplasma, we may classify in the following 

 way : — 



