598 MEDICAL ENTOMOLOGY 



GENUS RHIPICEPHALUS, KOCH, C. L. 



Capitulum short, basis capituli hexagonal, with lateral projections 

 on the dorsal aspect on each side. Palps short, broad and flat on the 

 dorsal surface, the external border straight or convex. First segment of 

 palp prolonged internally on the ventral surface and bearing a number 

 of feathery hairs ; the same border of the second and third segments 

 also with hairs. Hypostome with six rows of teeth. Spiracles comma - 

 shaped, Jong in the male and short in the female. Coxa I bidentate, 

 the internal spur broad and flat, the external conical; the remaining 

 coxae with very short external spurs ; tarsi with one or more spurs. Anal 

 groove present. Posterior festoons well marked in the male and in the 

 unfed female. Scutum usually inornate but sometimes marked with 

 clear spots. Eyes situated at the sides of the scutum, about half way 

 down in the female. (Neumann) 



The genus Rhipicephalus is essentially African ; a few species, how- 

 ever, are found in Southern Europe and some in Asia. It is represented 

 in America by one species, jR. sanguine us, and not at all in Australia. 



Neumann gives the following key for the determination of the species : 

 NEUMANN'S KEY TO THE SPECIES OF RHIPICEPHALUS 



MALES 



1. Eyes flat 



Eyes hemispherical ...,...,..., 22 



2. Marginal groove present ........... 3 



Marginal groove absent ........... 1 7 



3. Scutum unicoloured, brown .......... 4 



Scutum white and black pulchellus- 



(Zanzibar ; Somaliland ; Massailand ; Abyssinia ; German 



East Africa.) 



4. Adanal plates not prolonged into points (posterior borders 



straight or convex) 5 



Adanal plates prolonged into one or two points (posterior bor- 

 ders concave) .......... ..15 



5. Posterior border smooth or with a caudal appendage . . . . . . 6 



Posterior border with a caudal appendage .... aurantiacus. 



(Liberia.) 

 6 Adanal plates triangular or sub-triangular (internal borders 



straight or slightly concave) .......... 7 



Adanal plates sickle-shaped (internal border very concave, 



posterior and external borders forming a regular curve) . haemaphysaloides. 

 (China; Sumatra; Java; Borneo; Burma; India; Ceylon.) 



7. Coxa IV with very short spurs, much shorter than the coxa . , . 8 

 Coxa IV with long spurs, the external much longer than the coxa, gladiger. 



- (Congo.) 



