Annals of the Transvaal Museum. 



91 



. Males with small anal plates or without, but ventral 

 surface not covered with plates; anal furrow passing behind 

 anus and usually joining genital furrows, or wanting. 

 B. Males with two anal plates, usually acconipanied by an 

 accessory pair, eyes present ... {RlnpicepliaJeae .) 



C. Rostrum long ; palpi elongate and valvate 



H yalomma. 



CC. nostrum short; palpi short, broad, with an outward 

 projection on the second article. 



1). Anal groove present, stigmatic plates comma- 

 shaped in both sexes ... ... JUiipicephalus. 



1)1). Anal groove absent; stigmatic plates circular 



or oval MargaropuR. 



BB. Males with no ventral plates ; eyes sometimes present 



{AinhlyoiiiiDcae .) 



C. Eyes present. 



J). Palpi long, valvate; coxae IV not longer in 

 male than coxae I to III ; stigmata triangular 



A ))i blyom iiuf . 



Dl). Palpi short, thick; coxae lY much larger in 

 male than coxae I to III ; stigmata comma- 

 shaped, short. 



E. Palpi very short and wider than long; coxae 

 IV with two long spines ... Rhipicentor. 

 EE. Palpi longer than wide; coxae IV with- 

 out long spines ... ... Dermacentor. 



CC. Eyes absent. 



D. Palpi long; stigmatic plates comma-shaped. 

 E. l^ody as long as wide; anal groove present 



Aponoinma. 



li!E. Body wider than loiig^ ; anal groove not 

 present ... ... ... N eumanielJa . 



TJI). Palpi with a sharp projection outward; 

 stigmatic plates circular or short comma-shaped 



Haeiuapliy sails. 



Nyiuphs. 



(Key based on known Transvaal forms.) 

 Anal groove surrounds the anus in front oj^ening posteriorly. 



Erodes. 



. Anal groove surrounds the anus behind opening in front. 

 B. Palpi produced into a prominent lateral point. 



Hacmapli ysalis . 



BB. Palpi more or less cylindrical. 



C. Body circular in outline ; as wide as long 



Aponomma. 



CC. Body longer than wide. 



D. Body narrower behind than in front 



Margaropus. 



DD. Body as wide or wider behind than in front. 

 E. Shield pentagonal in outline; antero-lateral 

 edges occu|)ying three-quarters of the 

 length of the shield 



Rhipicephcdus . 



