Annals of the Transvaal Museum. 
115 
and projects slightly beyond the shield on the lateral and posterior margins,, 
the caudal prolongation also usually appearing at this time. 
I have been unable to obtain or rear the immature stages of each 
species, so that the study of these stages is incomplete. 
The following discussion, together with the keys, may serve to make 
the distinctions between the species more apparent. The drawings in the- 
plates are made from what seemed typical specimens, and will probably 
assist most in studying this difficult genus. 
Males of Rhipicephalus. (See Plates VIII and IX.) 
Among the males, evertsi is probably the most readily recognised,, 
because of its shagreened shield and also its saffron-coloured legs. Besides 
this the eyes are spherical and in orbits (VIII, a). 
R. oculatus resembles it closely in the matter of the eyes, hut although 
the punctuations on the shield are numerous, fine, and almost equal, they 
do not coalesce so as to give a shagreened appearance (VIII, 1). 
In capensis the shield is shagreened, hut here the eyes are not spherical,, 
hut flattened on the lateral margins (VIII, c ). 
R. sanguineus is the type species of the genus. The punctuating of 
the dorsal shield is here very distinct | the punctures are unequal in size, 
the smaller ones, more numerous, do not coalesce, hut are regularly dis- 
tributed ; the larger punctuations are fewer in number and are arranged 
in more or less regular fashion. There is a narrow posterior groove, with 
a large, oval, shallow pit on each side of it, with further forward two wider, 
smooth impressions ; the caudal prolongation is very short or may he want- 
ing (VIII, e). Another species known as punctatissimus was originally 
described by Gerstacker, and differed from mnguineus in the punctures being 
distributed more irregularly on the shield. Later studies made by Donitz 
seem to show that this species is synonymous with sanguineus or at most 
only a variety of the latter species, 
R. appendiculatus. — This species, together with bursa, ha, ye caused con- 
siderable confusion ; appendiculatus is easily recognisable by the elongate, 
slender caudal prolongation, but where this is not present the punctuation 
is typical (VIII, d). The large punctuations are mostly confined to the 
anterior end of the shield, but in a large area on each side at about the 
middle of the length of the shield the punctuations are very scarce and 
very superficial. There is not so much difference in the size between the 
large and small punctuations as is the case with sanguineus and other species 
of Rhipicephalus. The anal plates are also characteristic, both ends are 
pointed quite sharply, and the accessory anal plates are only indicated or 
lacking. 
R. bursa might be easily confused with appendiculatus, were it not 
for the anal plates, which are very broad, and not narrow and slender as 
in appendiculatus, there are also very small and slender accessory plates 
present. The punctuations of the dorsal shield are more even in size 
and distributed evenly over all its extent, a few large punctuations do 
exist, but they are situated near the margins and anterior end (VIII, h). 
The punctuations bring it near to capensis , which is, however, shagreened. 
R. simus is quickly recognised. It is larger than appendiculatus, 
and the shield is almost black in colour and polished so as to shine 
