24 Annals of the South African Museum. 



as for our purpose the lists given by Bolus are useless for comparison, 

 for the reason, as I have pointed out above, that he included East 

 Gi-riqualand, Basutoland, etc., in his Kalahari Region, and the former 

 also in the South-Eastern Region. These fresh lists have been 

 compiled from the collections in the South African Museum and the 

 Bolus herbaria, and from records given in the ' Flora Capensis.' 

 Bolus was conscious of the heterogeneous nature of his Kalahari 

 Region, as he states it "will hereafter almost certainly require to be 

 divided into several Regions, or at least to be subdivided into 

 Provinces." From an examination of collections made in the Transvaal 

 round Houtbosch (and Pietersburg) and Barberton (above 4000 ft.), 

 I also support this view, though I think Bolus was wrong in including 

 Barberton in his proposed Eastern Mountain Region. Unfortunately 

 I have not been able to examine sufficiently large collections from 

 these localities to make any definite statement as to the true affinities 

 of the floras, but from the data brought together I have no hesitation 

 in saying that they cannot be included in the Kalahari Region. This 

 being my view, I have excluded from the Kalahari Region as under- 

 stood in this paper, all species which occur in the neighbourhood of 

 the high mountain range forming the northern contination of the 

 Drakensbergen. 



The following reasons have led me to adopt this view : 



1. The presence of at least 7 species of Ericaceae in these regions, viz., 

 Erica alopecurus, Harv., E. alticola, G-. & B., E. Atherstonei, Diels., 

 E. cerinthoides, Linn., E. drakensbergensis, Gr. & B., E. subverticillaris, 

 Diels., and E. Woodii, Bolus. 



2. The presence of a large orchid flora. From Barberton 30 species 

 have been recorded, and from Houtbosch and Pietersburg 44 species. 

 The Kalahari Region contains 27 species of Orchidaceae, of which 

 only 7 species are common to either Barberton or Houtbosch. The 

 presence of epiphytic orchids is also significant. Megaclinium 

 Sandersoni, Oliv., Angraecum sacciferum, Lindl., and A. pusillum, 

 Lindl., occur at Barberton: Angraecum sacciferum, Liudl., and 

 A. tricuspe, Bolus, at Houtbosch. 



3. The paucity of species of Asclepiadaceae. This important order 

 of the Kalahari Region, which ranks fourth (with 119 species) among 

 the predominant Orders, is as far as my information goes, only 

 represented at Barberton by 16 species and at Houtbosch by 12 species. 

 This paucity of species is also very noticeable in the Acanthaceae and 

 Convolvulaceae, both of which are characteristic Orders of the Kalahari 

 Region. 



It is probable that when the floras of Barberton and Houtbosch are 



