TICKS OF THE BELGIAN CONGO. 32-^ 



Genus 5. Rhipicephalus. 



Generic characters : Usually inornate, with eyes and festoons, with short palps, and 

 basis capituli usually hexagonal dorsally, coxa I. bifid. The male possesses a pair of 

 adanal shields and usually a pair of accessory adanal shields ; some males, when fully 

 fed, show a caudal protrusion. Sjnracles co^nma- shaped. 



Nine species of Rhijncephalus are recorded from the Congo. It is a difficult matter 

 to determine the species of this genus because of individual variations in size and 

 structure as illustrated in figs. 18, 19, 25 and 26 relating to two species which occur 

 in the Congo. When typical examples are examined the difficulty is considerably 

 lessened, especially in the case of the males. The females are more difficult to deter- 

 mine and the beginner is advised to obtain expert opinion before reaching conclusions 

 with regard to the species with which he is dealing. The following main characters 

 will be helpful in roughly determining typical male specimens of the nine Congo 

 species : — 



(1) R. appendiculatus, Neumann, 1901. Characterized by adanal shields tending to 

 be pointed posteriorly, scutum with many punctations. Coxa I. prominent 

 when viewed dorsally. Note the shape of the basis capituli in the 

 accompanying illustration. Fully fed males have a long caudal process 

 (figs. 18-21). For biology see p. 344. 



For figs. 18-21, see pages 324, 325, 326. 



