Ixodoidea. Ticks. 117 



Capitulum hidden under a projecting beak-like prominence 

 (hood), so close to anterior margin that the tips of the 

 palpi project from under the body and are visible from 

 above ; eyes present or absent. Ornithodorus 



Family IxoDiD^. 



3. Palpi short, sub-triangular, not, or only slightly longer than 



broad ; Capitulum short ; front of body emarginate for 



insertion of capitulum. Rhipicephalinae 



Palpi longer than broad ; capitulum long ; point of body 



straight or emarginate. IxOdinse 



Subfamily Rhipicephalin^. 



4. Second and third palpal articles straight, not drawn out later- 



ally into sharp points ; stigmata comma-shaped. 



Rhipicephalus 



Second and third palpal articles drawn out laterally into sharp 

 points ; stigmata nearly round. Boophilus 



Coxse I not bidentate ; coxae IV of normal size ; eyes ab- 

 sent. Haemaphysalis 



Coxse I bidentate in both sexes ; coxse IV much larger ■ than 

 I to III ; eyes present. Dermacentor 



Subfamily IxODiN>^. 



5. Palpi valvate on median surface in both sexes. Ixodes 

 Palpi claviform, not valvate in male ; legs very long. 



Eschatocephalus 

 Eyes absent; anal plates absent. Aponomma 



Kyes present ; anal plates absent. Amblyomma 



Anal plates present on males. Hyalomma 



TICKS. KEY TO GENERA AND SPECIES. 



Subfamily Rhipicephalin^. 



Subfamily Diagnosis. Ixodidse : Palpi short, conical, usually 

 longer than the hypcstome. 



Type Genus. Rhipicephalus. 



Genera : Rhipicephalus, Boophilus, HcBmaphysalis and Der- 

 macentor. 



(Neumann denies that Boophilus is in any sense a separate 

 genus"). 



