4 
Annals of the Transvaal Museum 
Transvaal Museums, is presented as a guide to the characters and gross 
distribution of the various genera and species now known to inhabit 
South Africa, the northern limits of which are the Zambesi and Cunene 
rivers on the east and west sides respectively: all the distribution data 
of earlier authors have been incorporated, but for detailed descriptions 
of the various species reference must be made to the original accounts. 
SOME GENERAL REMARKS ON THE EXTERNAL 
STRUCTURE OF SOLIFUGAE. 
Some of the external characters presented by the Solifugae are very 
stable: the segmentation of the body and of its appendages (excluding 
the tarsi of the legs), and the position of the various apertures of the 
body, are thus not available for systematic purposes. The most important 
characters employed in the classification of the S. African forms are: 
The segmentation of the tarsi of the legs, the structure of the male 
flagellum, the nature of the dentition, and the modification of the hairs 
and bristles which clothe the various surfaces. Most workers have also 
attached considerable importance to the features of the very character- 
istic rostrum or camerostome 1 which has the mouth at its apex, but such 
variations as do occur in this structure amongst the various genera are 
not very striking, and seem to me of doubtful value in a natural classifi- 
cation. 
The segmentation of the body is described in a general way in most 
text books of invertebrate zoology, and can be easily determined from 
fresh specimens or spirit-preserved material. Some confusion may arise 
in the case of Hexisopus and Chelypus where the tergites of the abdomen 
are not strongly chitinised, and thus are not easily distinguished. A 
source of difficulty may also be found in the segmentation of the thorax, 
the dorsal sclerites of which are much reduced in all Solifugae. In the 
accompanying figures, the relationship of these sclerites to the appen- 
dages has been indicated in accordance with the views expressed by 
Mr H. M. Bernard in his important treatise on the morphology of this 
order (27). 
It should be mentioned, however, that the celebrated arachnologist 
W. Sorensen has recently presented a different interpretation of the 
sclerites behind the head-plate (28). He recognises only two thoracic 
tergites, viz. those labelled as third and fourth in this paper: according 
to him, those here labelled as first and second cannot be true tergites, 
because the elevator muscles of the appendages are not inserted thereon. 
Sorensen thus interprets the structure of a solifuge: head bearing four 
1 This has been homologised by Croneberg and by Gaskell (see The Origin of 
Vertebrates, pp. 222, 223) with the first antennae of Crustaceans: for another view see 
Bernard’s monograph. The terms applied in this paper to the various appendages 
are those in current use amongst Arachnologists, and have no reference to their 
respective homologies with the appendages of other Arthropods. I may remark that 
the very characteristic chelicerae — sometimes unfortunately termed the mandibles — 
are apparently homologous with the second antennae of Crustaceans and with the 
antennae of insects, whilst the pedipalpi or palps are homologous with the mandibles, 
of other Arthropods. 
