276 Mr. O. Thomas on 
Closely allied to the typical G. stagmonya, Heugl.*, from 
Khartoum, but more heavily built and the colour sandy buffy 
throughout, very much as in G. pecilops, instead of yellowish. 
Darker nose-mark and four white facial marks present as 
usual. White of throat spreading up towards the eyes on 
the cheeks, but not quite reaching them, a narrow line of 
buffy passing across. 
Skull as in sé2gmonyx, but heavier; the palatal foramina 
rather more open. 
Dimensions of the type (measured in the flesh) :— 
Head and body 95 millim. ; tail 110; hind foot 23; ear 12. 
Skull: greatest length 28; basilar length 21; greatest 
breadth 14; length of nasals 10; interorbital breadth 4°8 ; 
parietal breadth 12°2; interparietal 3°5x7°5; palatine fora- 
mina, length 4:7; diastema 7:2; length of upper molar 
series 3°6. 
In the Anderson collection there are two skins from the 
neighbourhood of Khartoum, obtained by Mr, H. F. Witherby, 
which Mr. de Winton thinks, and I agree with him, may be 
taken to represent Heuglin’s stiymonyz, though the description 
might apply to several other species f. ‘’his animal is allied 
to the Aden G. pociiops, having somewhat similar propor- 
tions and skull-structure. The soles of the hind feet are of 
the Dipodilius type, but have a number of fine scattered 
hairs on them in the region of the pads, more typical Dipodilli 
having the soles entirely naked. In this respect, as in others, 
Mr. Hawker’s gerbille agrees with the Khartoum form, and 
differs from the more northern G. (V.) Bottat and quadri- 
maculatus. 
12. Mus musculus orientalis, Cretzschm. 
g. Khartoum. 26th January. 
The local form of the house-mouse. Apparently represents 
Mus pallescens, Heugl. 
13. Mus macrolepis, Sund. 
9 ¢,1 9. Kaka, 23rd Apnil. 
@. Duem. 21st May. 
46,3 2. Fashoda. 28th to 30th March, 2nd April. 
In working out this most difficult group of the genus these 
specimens, as certainly representing Sundevall’s species (“ex 
* Reise N.O.-Afr. ii, p. 78 (1877). 
+ The specimen marked steymonyx in the Stuttgart Museum does not 
at all agree with Heuglin’s description, and cannot be the type. It is 
probably a member of the Gerbillus gerbillus group. 
