Annals of the Transvaal Museum. 
90 
longest ; with six (8) articles, the third and the tarsi presenting^ a false 
articulation near the proximal end, except in the tarsi of the first pair, 
where it is near the distal end ; tarsi provided with a cup-like 
ambulacre, produced from a caruncle, folded more or less fan-like on 
the ventral surface of the claws. Integument coriaceous, extensible, 
reinforced by a dorsal shield, emarginated to receive the base of 
the rostrum, often ornamented with designs and bri ght 
colour, grooved in front by two longitudinal grooves (cervical grooves), 
starting from the angles of emargination at base of rostrum. 
Stigmatic plates situated behind the coxae of the fourth pair of legs. 
Sexual opening median transverse, placed more or less in front, 
between the coxae of the first three pair of legs ; from the commissures 
of that orifice start two grooves ( sexual grooves), which extend back- 
wards and diverge more or less, terminating at a variable distance 
from the posterior margin. Sexual dimorphism very marked; the 
male is ordinarily smaller than the female, more flattened and often 
of a less regular oval contour ; the anterior extremity being much 
more narrow than the posterior ; the dorsal shield covers all the body 
or leaves uncovered only a marginal band ; the posterior border is 
usually divided into eleven quadrangular festoons, extending between 
the dorsal extremities of the two stigmatic plates, and often prolonged 
on to the ventral surface ; the ventral surface often presents shields 
and plates, the number and form of which are variable. The female 
is flat at first, but from the development of the enormous quantity of 
eggs, can become of a considerable volume by the extension of its 
integument in the three dimensions ; the dorsal shield is limited to the 
anterior part and preserves its original dimensions during distention 
of the body; the posterior portion of the abdomen often presents (in 
the young) eleven festoons. The dorsal surface of the base of the 
rostrum has two symmetrical pits (porose areas), with very fine 
punctuations, which are lacking in males, nymphs, and larvae. 
This sub-family is divided into three tribes — the Ixodeae, 
Rhipicephaleae , and the Amblyomeae. 
Ixodeae. — Males clothed on all their ventral surface with shields. 
Anal furrow of both sexes passing around anus in front, and separate 
from the genital furrows; no eyes. Rostrum elongate. Includes the 
genus Ixodes. 
Rhipicephaleae. — Males provided with one pair of anal shields, 
ordinarily accompanied by accessory shields. Anal furrow of both 
sexes passing around the anus behind, and usually joining the genital 
furrows in front. Eyes present. Rostrum sometimes long and some- 
limes short. Includes the genera Rhipicephalus , Mar gar opus , and 
Ilyalomma. 
Amblyomeae. — Males without anal shields. The anal furrow 
surrounding the anus behind and usually joining the genital furrows 
in front. Sometimes with eyes. Rostrum long or short. Includes 
the genera Amblyomma, Aponomma, Neumaniella, Rhipicentor, 
Derrnacentor, and Haemaphy salts. 
The various genera of this sub-family may be separated by the 
following key : — 
Adults. 
A. Males clothed on all their ventral surface with shields; anal 
furrow of both sexes passing around anus in front, and not 
joined to the genital furrows ... ... (Ixodeae) , Ixodes . 
