Annals of the Transvaal Museum. 
91 
A A. 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 accompanied by an 
accessory pair, eyes present ... (. Rhipicephale.de .) 
C. Rostrum long ; palpi elongate and valvate 
Hy diorama. 
CC. Rostrum short ; palpi short, broad, with an outward 
projection on the second article. 
D. Anal groove present, stigmatic plates comma- 
shaped in both sexes ... ... Rh Iplcephalus . 
DD. Anal groove absent; stigmatic plates circular 
or oval Mar gar opus. 
BB. 
Males with no ventral plates ; eyes sometimes present 
(. Amblyommeae .) 
C. Eyes present. 
D. Palpi long, valvate; coxae IY not longer in 
male than coxae I to III ; stigmata triangular 
Amblyomma. 
DD. Palpi short, thick; coxae IY much larger in 
male than coxae I to III; stigmata comma- 
shaped, short. 
E. Palpi very short and wider than long; coxae 
IY with two long spines ... Rhiplcentor. 
EE . Palpi longer than wide ; coxae IY with- 
out long spines ... ... Dermacentor. 
CC. Eyes absent. 
D. Palpi long; stigmatic plates comma-shaped. 
E. Body as long as wide; anal groove present 
Aponomma. 
EE . Body wider than long ; anal groove not 
present ... ... ... Neumaniella. 
DD. Palpi with a sharp projection outward; 
stigmatic plates circular or short comma-shaped 
Haemaphy sails. 
Nymphs . 
(Key based on known Transvaal forms.) 
A. Anal groove surrounds the anus in front opening posteriorly. 
Ixodes. 
A A. Anal groove surrounds the anus behind opening in front. 
B. Palpi produced into a prominent lateral point. 
Haemaphy sails. 
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 
Mar gar opus. 
DD. Body as wide or wider behind than in front. 
E. Shield pentagonal in outline; antero-lateral 
edges occupying three-quarters of the 
length of the shield 
Rhlplcepha lus . 
