1908.] MAMMALS FROM ZAMBESIA. 547 



We take this opportunity of describing a seconrl local race of 

 M. chri/soj)hilus :— 



MUS CHRYSOPHILUS ACTICOLA, SVxbsp. n. 



A large coast form of If. chrysophilits, the liind foot alwa-ys 

 niai-kedly longer than in that animal. 



Size somewhat larger than in true 21. chrysojyJiilus. 



General colour as in the type form, but tlie slaty bases of the 

 hairs of the under surface markedly shorter and very much paler 

 than in the true chryso'philus, in which the slaty bases of the hairs 

 of the lower surface of the body do not differ materially in shade 

 from those of the back. 



Skull larger than in the typical subspecies, but the bull* 

 slightly smaller. Height at m" 10 mm. 



Dimensions of the type : — 



Head and body 155 mm. ; tail 202 ; hind foot 34 ; ear 23. 



Skull — greatest length (c.) 39 ; basilar length 30*5 ; zygo- 

 matic breadth 19 ; brain-case breadth 15 ; nasals length (c.) 15 ; 

 diastema 10 ; molars 6*2. 



Hah. Coast between Limpopo and Zambesi Rivers (type from 

 Beira). 



Tyj^e. Adult male. B.M. no. 7.6.2.59. Original number 1752. 

 Collected 25th December, 1906, by C. H. B. Grant (Rudd Ex- 

 ploration). 



The type of M. c. acticola is of about the same age as that of 

 true M. chrysopMlus. In a long series of adult specimens from 

 Inhambane and Beira the hind foot is recorded as low as 30 mm. 

 in only three specimens, whereas in a large number of typical 

 M. chrysoiohilus it never exceeds 29, The tail would seem to be 

 proportionally quite as long as, or even longer than, in M. c. 

 ineptus. 



24. MuS AVARILLUS, sp. n. 



$. 1980. 



A mouse outwardly resembling 21. namaquensis, hut with the 

 teeth of 2f. chrysophilus, of which it is probably a dwarf relative. 



Size rather smaller than in 21. namaquensis. Fur soft and 

 silky, but rather short (8-9 mm. on the back, 5-6 on the belly). 

 Colour as in 21. namaquensis, but the shorter coat allowing the 

 basal slaty portion of the hairs to show through gives the upper 

 side a duller general colour and makes the belly greyish white 

 instead of the apparently pure white of namaquensis. 



Skull a copy in miniature of 21. chrysophilus. Teeth as in that 

 species. 



Dimensions : — 



Head and body 105 mm. ; tail 143 ; hind foot 26 ; ear 21. 



Skull — gi-eatest length 31 ; basilar length 23; greatest breadth 

 14; brain-case breadth 12*5; interorbital breadth 4-9; nasals 

 11*6 ; diastema 7*6 ; upper molar series 6 ; bullae 5* 3. 



