8 
Annals of the Transvaal Museum 
which the third leg on the right side has a seven-jointed tarsus, like the 
fourth leg, whilst that on the left side is four-jointed as usual: the right 
third leg is apparently not abnormal in any other way, the basal portions 
being like those of a normal third leg. 
The spinulation of the legs is also a very constant character within 
the same genus. Spines are most strongly developed in the genus 
Solpuga, where legs III and IV are spined as follows: Fourth leg, patella 
with a pair interiorly near the apex, tibia with five (sometimes six or 
four) on the anterior surface, and three (but varying from two to five) 
on the posterior surface, tarsus with ten pairs interiorly (or ii-io) : 
Third leg, patella with two at the apex superiorly and three on the 
inferior surface, including a pair at the apex, tibia with five superiorly 
and three pairs inferiorly (occasionally 4-3 or 4-4), tarsus with seven 
pairs inferiorly. The first leg is completely devoid of spines, and the 
second leg is spined more or less like the third but the tibia may have 
3*2 or 2-i spines ventrally and the tarsus four spines or none externally 
above. These are all strong spines : in addition, there may be shorter and 
weaker ones on the second and third tarsi inferiorly. 
In all other genera the number of spines on the tarsi are fewer: in 
Daesia, the tarsus of leg IV has three pairs of spines infero-laterally. 
EXTERNAL SEXUAL DIFFERENCES. 
Externally, the sexes are distinguished primarily on the characters 
of the first abdominal sternite (it is actually the second sternite according 
to Sorensen). This genital sternite is seen in its simplest form in the adult 
female of the genus Lipophaga, where the two flaps, representing a pair 
of appendages, remain quite distinct from each other and either one can 
be raised independently: the posterior mesial angle of each flap is acute. 
In other genera, these flaps are firmly united along the midline by 
membrane: sometimes, as in Solpuga Venator, union takes place along 
the whole length of the flaps, and their hind borders are broadly rounded 
on each side : occasionally, as in Solpuga chelicornis and hostilis, an acute 
posterior lobe at the apex of each flap remains free, a condition which 
presumably is more primitive than that of Venator. The female genital 
aperture lies in the soft skin posterior to and protected by the sternite, 
and is quite large in adults. In adult females of Solpuga there is often 
a small brown scar or several scars on the anterior portion of the genital 
sternite mesially: this is presumably a mark made by the male during 
the mating process and is thus indicative of sexual maturity 1 . 
On the other hand, the genital aperture of the adult male opens on 
the surface of the same sternite. The two halves are united together, 
but in the middle they enclose a pair of long convexly raised sclerites 
between which mesially is the elongated slit-like genital aperture. These 
sclerites occur in young males as well as in adults but are much larger in 
the adults relatively as well as absolutely. 
1 An account of the mating habits of Galeodes is given by R. Heymons in a paper 
entitled ‘ ' Biologische Beobachtungen an asiatischen Solifugen” in Abh. Preuss. Akad. 
Wiss. Berlin, 1901. 
