92 
Annals of the Transvaal Museum. 
EE. Shield eordiform in outline. 
F. Eyes hemispherical ... Hyalomma. 
FF. Eyes flat ... ... Amhlyomma- 
Larva . 
(Key based on known Transvaal forms.) 
A. Body much longer than wide ; narrowed at both extremities. 
Ixodes.. 
A A. Body as long as wide, or longer than wide, but widely 
rounded behind. 
B. Palpi produced into prominent lateral points. 
H aemayhy salis . 
BB. Palpi more or less cylindrical. 
C . Body as wide as long ; circular in outline 
Aponomma .. 
CC . Body longer than wide. 
I). Palpi very short and thick ... Mar gar opus - 
VD. Palpi elongate. 
E . Palpi of medium length ; more or less 
pointed at tips ; dorsal shield allows a 
portion of the body to show along its 
antero-lateral edge ... Bhipicephalus . 
EE. Palpi very long; dorsal shield covers all 
of anterior portion of body. 
F. Eyes hemispherical ... Hyalomma - 
FF. Eyes flat ... ... Amblyomma - 
GENUS IXODES, ( LATREILLE .) 
Acarus (ex. p.), Linnaeus (1758). 
Ixodes, Latreille (1795). 
Cynorhaestes (ex. p.), Hermann (1804). 
Crotonus (ex. p), Dumeril (1822). 
Ixodes, (Latreille), (Neumann, 1899). 
Eyes absent. Palpi long. Anal groove opened or closed behind,, 
but tangent to the anus by its anterior concavity. No terminal spurs’ 
on the tarsi. The male with the ventral surface covered with plates, 
as follows : — One pregenital plate between the sexual opening and 
the rostrum ; two lateral epimeral plates more or less surrounding 
the stigmata and coxae ; a genito-anal plate, of elongate pentagonal 
shape, between the sexual opening and the anus ; an anal plate, 
triangular, pointed or circular, behind the preceding, the anterior 
end surrounding the anus, the base formed by the posterior margin 
of the body ; two quadrangular adanal plates, parallel to the anal 
shield ; dorsal shield leaving a margin more or less wide, uncovered 
on lateral and posterior margin of body; no posterior festoons. 
Stigmatic plates oval. Female with three longitudinal grooves on the 
posterior part of the dorsal surface ; on the ventral surface two long 
genital grooves, extending from the sexual opening, and diverging 
caudad ; also two small anal grooves united in front of the anus,, 
parallel or diverging behind, rarely converging. Stigmatic plates* 
circular. 
