segments thicker in the middle forming a sharp angle 

 externally. First segment has not five or seven 

 bristles on its ventral inner chitinous plate as Eurhifi- 

 cephalus has ; (5) Coxa I only slightly incised, with 

 two stumpy processes. <? very small, about two 

 millimetres. Scutum very convex, punctate, four 

 rows of hairs. Two pairs of anal plates having their 

 sides parallel, not triangular. External plate as long 

 as internal. 



$ . Very small scutum, posteriorly it is V-shaped, 

 not polygonal as in Eurhipicephalus. 



Bionomics. Ticks of this genus remain on their 

 host all their life, from the larval stage till they drop 

 off to lay eggs. From egg to adult stage lasts about 

 three weeks and the whole life is about nine weeks. 



Neumann considers that there is only one species, 

 viz., M. annulatus ( bovis\ and that australis 

 decelerates, caudatus, etc.) are merely varieties. Donitz 

 considers that there are at least two species. 



(1) M. decoloratus.Tht blue tick. 3. The 

 four anal plates all end in a sharp point, often projecting 

 beyond thejhind margin. First segment of palpi on 

 the lower and inner side has a stumpy appendage 

 bearing a single bristle. Tail present. Radula (hypo- 

 stome), six rows of teeth. Rhodesia, Cape Colony. 



Pathogenicity. Transmits P. bigeminum. 



(2) M. annulatus ( Boopbilus bovis and M. 

 australis). The common blue tick. Tail absent. 

 Radula, eight rows of teeth. Japanese varieties have ten 

 rows of teeth. Anal plates have stumpy ends. 



Pathogenicity. Transmits P. bigeminum. 



GENUS HAEMAPHYSALIS 



Base of rostrum rectangular, twice as broad as 

 long. Eyes absent. Anal shields absent in $ . Second 



