es of Opisthophthalmus. 137 



State, and is apparently quite separated geographically from any 

 other species of the section. In the Cedarberg Range in Clamvilliam 

 one species without the forked groove is found, while Little Bush- 

 manland harbours representatives of both sections. 



I shall first consider the region occupied by the species provided 

 with a forked groove. 



Starting from the south-west and proceeding northwards, we meet 

 in succession with four closely related forms, viz., capensis (Cape 

 Town and neighbourhood), var. fuscipcs (Paarl and south-western part 

 of Tulbagh), Icipoldti (Clanwilliam), and granifrons (highlands of Van 

 Ehynsdorp and Namaqualand). Characteristic of these four forms 

 is the coarse granulation on the ventral surface of several posterior 

 abdominal segments in the adult male and of the last segment in the 

 female. This granulation is always present in the mesial part of the 

 segment, even if absent from the sides. Related to granifrons but 

 differing chiefly in the smoothness of the sterna (except in the case 

 of the male of the first) are granicauda and ater from Namaqualand, 

 schlechteri from Little Bushmanland, and laticauda from Calvinia. 

 All these species, together with crassimanus and probably also 

 pictus, appear to form a natural group, characterised by the median 

 groove of the carapace forked anteriorly (except in crassimanus), the 

 terminal tooth of the superior caudal crests enlarged (except in var. 

 fuscipcs), the fourth tarsus with few spines, there being generally 

 none, rarely one, on the exterior part of the inferior surface, and 

 often only three on the external terminal lobe, the hand in the 

 male (except in capensis and leipoldti) generally granular above and 

 like that of the female but narrower, the scape of the pectines in the 

 male generally free of teeth at base behind (except in capensis), and 

 the racket-shaped laniellas on basal joint of mandibles absent or only 

 1-3 in number. 



0. pallid ipes and peringueyi form a small group apparently not 

 related to the granifrons group and having the hand in the adult 

 males very long, slender, and smooth above. 0. pallidipes extends 

 over almost the same area occupied by the granifrons group (from 

 Piquetberg to Namaqualand), occurring in abundance, however, only 

 in places where no representatives of the latter group are found. 

 The fourth tarsus is many-spined, being always provided with 1-3 

 external spines below and 4 on the external terminal lobe. The 

 terminal tooth of the superior caudal crests is enlarged, and the 

 lamellae on the basal mandibular joint may be present or absent. 



Passing to the species in which the median groove of the carapace 

 is not forked, we find in the first place a small group of three forms 



