172 
Annals of the Transvaal Museum. 
connection with a species of Dermacentor . A second examination 
of Rhipicephalus glad/iger -brought me definitely* to the conclusion 
that the anal shields were absent. Rhipiceph'ctlus is, therefore, no- 
more in question. It is apparently an intermediate form between 
Rhipicephalus and Dermacentor. On the 21st of' December I wrote 
to Mr. Howard that I intended to reunite the two species in a new 
genus which I proposed to call Rhipicentor. 
It seems that the same thing occurred to Messrs. Vuttall and 
W arburton, for, by a rare coincidence, it is the same name chosen 
by them in a recent work* in which they describe, under the 
name of Rhipicentor bicornis, the species which I called Rhipicephalus 
gladiger. At the same time they gave the characters of the new 
genus which they establish in that paper. The publication of this 
work of Nuttall and Warburton having preceded my “ Notes:' VI,” 
it is evident that Rhipicentor bicornis must have the preference over 
Rhipicentor gladiger. 
A comparison of the two species of the new genus show the- 
following principal differences : — 
Rhipicentor bicornis. Rhipicentor vicinus . 
Male . — Base of rostrum, 
with posterior angles prolonged 
into a spine. Coxae IV with 
spines unequal, the inner one 
almost double the outer one. 
Female . — Dorsal shield 
scarcely longer than wide. Palpi 
short. Coxae IV with spines 
longer than wide. 
Male . — Base of rostrum y 
with posterior angles simply 
projecting. Coxae IV with 
spines almost equal. 
F e m a l e . — Dorsal shield 
scarcely longer than wide. Palpi 
long. Coxae IV with spines as 
wide as long. 
* Gr. H. F. Nuttall and C. Warburton. On a new genus of Ixodoidea, together with a 
description of eleven new species of ticks. Proc. of the Cambridge Philosophical Society, vol. 
XIV. 1907, p. 398. 
