KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 48, N:o 5, 97 
Acomys percivali Do_uman. 
Dotuman: Ann. & Mag. Nat. Hist., Ser. 8, Vol. VIII. p. 126. 
Fourteen specimens of this dark slate-coloured Spiny Mouse were collected north 
of Guaso Nyiri at the water place Njoro, and below Chanler Falls. Some of the spe- 
cimens were damaged by the ants and many destroyed. The same was the case with 
the following species. As soon as the mice had been killed in the traps, the ants 
devoured their nose, feet, ears ete. so that many specimens had to be thrown away. 
The dimensions of my specimens agree on the whole with the measurements 
recorded by DotitMAN. Some of my specimens have, however, the tail measuring as 
much as 90 mm. The dimensions of the skulls are perhaps generally a little smaller 
than those recorded by DoLtuMAN as may be seen from the following table of mea- 
surements for which only skulls with worn teeth have been used: 
a aa pey @ | 9 
mm. mm. mm. | mm. 
CGOMGRSE TANG. ss ws ke Sw Sekt Os 27,3 | 26,3 / 26,3 | 25,3 
Condyloincisive length ........ 24.6 23,5 24,2 22.8 
| Zygomatic breadth .......... eT? ‘igs Bees 108 
}, Minterorbifal breadth: :) «©... as). Si). 44 | 4,2 | 4,4 | 4,4 
None of my specimens exhibits any rufous phase, but some are darker than the 
others. 
This species is evidently common in the thornbush country north of Guaso 
Nyiri below Chanler Falls. 
Acomys kempi DotiMay. 
Dottman: Ann. & Mag. Nat. Hist., Ser. 8, Vol. VIII. p. 125. 
Fourteen specimens of this bright-coloured Spiny Mouse were collected in Febr. 
and March 1911 at various localities on the northern side of Guaso Nyiri from a 
place not much east of the ford on the Marsabit road, and to some distance below 
Chanler Falls in the east, and northwards as far as at the water place of the Rendiles 
called Njoro. The type locality recorded by Dotan (I. c.) is included in this area. 
Some of my specimens have been damaged by the small but extremely voracious 
ants of this thornbush-country, which entirely spoiled several more specimens of 
this mouse as well as others. Those which I have preserved in a good state prove 
that the variation of the length of the tail is much greater than Dot~Man could 
observe on his two specimens. It varies in adult specimens from less than 90 mm. 
to 107 mm. The length of head and body recorded appears to be rather too great. 
K. Sv. Vet. Akad. Hand]. Band 48. N:o 5. 13 
