492 MKSSllS. OLDFIELD THOMAS AND M. A. C. UINTON ON 



structures being perforated by tunnels just large enough for them 

 to pass through. 



Nocturnal. Feeds largely on the seeds of Kamel-thorn and 

 other leguminous bushes. Not attracted by cultivation." 



21. Ra'itus (Mastomys) coucha A. Sm. 



6. 57, 151, 191-194 (young), 266, 296. ? . 191, 192 (young), 

 313, 316. Louisvale. 



" Fairly plentiful, but far outnumbered by lihahdomys pumilio, 

 I'atera, Desmodillus, etc. Nocturnal : attracted by cultivation, 

 and sometimes entering houses. Immature individuals are very 

 different in colour from adults, being dark bluish slate." 



22. Mus MuscuLus L. 



d . 135, 235, 241. $ . 105, 113, 303, 373. Louisvale. 



" Fairly plentiful in stores and houses, but, as elsewhere, has 

 not taken to an outdoor existence as it lias done in Australia. ; 

 possibl}' finding it difficult to compete in this country with the 

 large number of small indigenous rodents. 



Imported house rats have not yet found their way to settle- 

 ments along this part of the river, probably on account of the too 

 recent extension of the railway." 



23. Rhaddomys pumilio bechuan^ Thos. 

 42 specimens. Louisvale. 2600'. 



The deep grey Namaqua form griseus is readily distinguishable 

 from any of these specimens, but the paler deserti of the Kalahari 

 is more doubtfully separable. 



Several examples from Louisvale have the hind foot recorded 

 as 27 mm. in length, the same as in the oi-iginal type, while 

 others have the foot considerabl}'^ shorter. In colour also there 

 is marked variation in the general tone. 



The skulls have unusually heavy supraorbital ridges, and their 

 bullae are larger than in most forms of the group — about 7*0 mm. 

 in length. 



" Diurnal. Particularly plentiful in the vicinity of cultivation, 

 where it probably outnumbered all other small rodents," 



24. Thallomys shortridgbi, sp. n. 



d. 169, 170 (young). $.1,180,181. Louisvale. 



" Shot in tree. Arboreal, not occurring away from the 

 wooded area along the river bank. Not plentiful. Mammai 

 0-2 = 4."— G. 0. S. 



A brown species with very slightly developed face markings. 



Size about as in nigricauda, or slightly smaller. General colour 

 above brown — near " Brussels brown " — not so greyish as in other 

 species. Under surface white, but the bases of the haiis are 



