A Survey of the Scorpion Fauna of South Africa. 
177 
practically so in the female of militum). The middle lateral crest of caudal 
segment IV is distinguishable, but very weak. The intercarinal surfaces on 
the sides and lower parts of the tail, except on the first segment inferiorly, . 
are finely granulated ; in the female of militum the intercarinal surfaces 
are practically smooth on the first three segments and only sparsely granu- 
lated on IV and V, the first segment also having a few granules on the sides. 
Hand of male much stouter than in the female. Vesicle and last two < 
caudal segments yellow, like the rest of the body. 
Measurements of P. laevifrons concolor and female of laevifrons militum : ' 
Female of 
P. laevifrons concolor. 
laevifrons 
militum. 
Total length .... 
. M. 75 
F. 97 
Length of fifth caudal segment . 
. M. 9-3 
F. 10-75 
8 
Length of movable finger . 
. M. 8-7 
F. 9 
7-2 
Breadth of hand 
. M. 3-9 
F. 3-6 
3-4 
Breadth of brachium measured 
at 
base of anterior spine 
. M. 2-9 
F. 3-4 
31 
Parabuthus laevifrons australis, Hewitt. 
Upington (Miss H. Lennox). 
In this specimen, an adult male, all the ridges on the stridulatory 
area of the second caudal segment are quite short, and that area is not 
narrowly channelled. The vesicle is not deeply excavated at the base, 
and the fourth caudal segment is only very slightly narrower than the 
first, although in the male of concolor the fourth caudal segment is more 
distinctly narrower than the first. The fifth caudal segment is coarsely 
granulated on the sides superiorly. The fingers are slightly bowed basally, 
so that the cutting edges do not meet except near the tip ; in the male of 
concolor the fingers meet along their whole length, being longer and straighter, 
and the hand not so much swollen as in australis. 
The middle and hinder portions of the superior keel of the fifth caudal 
segment are quite obsolete in females of concolor and of militum; in the 
male of australis a few strongly developed granules representing that keel 
.are present in the posterior half of the segment ; in the male of militum 
some coarse granules occur there, but as they are not well separated from 
the granules of the sides of the segment, the posterior portion of the keel 
cannot be described as present. 
The three varieties of laevifrons here recognised are therefore mainly dis- 
tinguished as follows : australis, the primitive form, has the stridulatory areas 
of the second caudal segment in both sexes devoid of well-developed ridges, 
and the vesicle is not deeply excavated at the base superiorly in either sex ; 
concolor has the stridulatory areas of that segment in both sexes confined to 
