MAMMALS FROM KGYPT AND SINAI. 229 



in the Watli Natron two examples of white mice, with tlie note 

 that they were quite common in the Salt Company's buildings. 

 These are apparently ordinary albino mice, similar to those which 

 are domesticated throughout Europe. There is, however, no 

 evidence to sho\v whether these arose " spontaneously " or were 

 imported by some previous occupant of the buildings and then 

 escaped. I have asked Mr. NicoU to try to procure further 

 information on this point and also as to whether normal-coloured 

 and piebald individuals are also found. 



AcoMYS RUSSATUS Wagner. 



Acomys russatus Wagner, Abh. Akad. Miinchen, iii. p. 195, 

 pi. 3. fig. 2 (1840) ; Tristram, Fauna Palestine, p. 11, pi. 3. fig. 1 

 (1884). 



I have received a pair of these rare mice alive from Sinai, the 

 typical locality. This pair, which I received on M.iy 3rd, gave 

 birth on the 10th to three young. These were born, as in the case of 

 A. cahirinus*, in a very forward state of development, being very 

 large and covered with hair aiid spines ; they grew very rapidl}' and 

 were about half grown and well able to fend for themselves when a 

 fortnight old. They differ strikingly in coloration from the adults, 

 being of a uniform pale grey throughout; when three weeks old the 

 new adult coat of a lighter tint became visible on the nnder parts, 

 and a week later the fii-st trace of the yellow colour of the upper 

 parts began to show on the shoulders ; this coat gradually spread 

 backwards towards the tail in a brf)ad stripe along the centre of 

 the back, the adult dress being finally completed along the flanks 

 at the age of six weeks, by which time they were full-grown. I 

 have been unable to note the exact period of gestation, but it is, 

 I fancy, slightly longer than in the case of A. cahirinus. 



This s^^ecies is of a deep reddish bi-own on the back, each spine 

 having a darker apex ; the head is greyer and the nnder parts 

 are gre^'ish white, there being no sharp line of demarcation 

 between the colours of the upper and under parts, as is the case in 

 all other species of this genus, except A. cahirinus. The tail is 

 short, being only about two-thirds the length of the head and 

 body, and appears almost black, although it is sparsely covered with 

 minute whitish hairs. 



In my previous paper t I referred a. specimen of an Acomi/s 

 taken just outside Cairo to A. ccihirinus. Since then I have 

 received a second example obtained by Mr. NicoU in the Wadi 

 Hof near Helouan, and through the kindness of Capt. Flower I 

 have also received, as noted .above, a pair of Acomys rtissatus n\i\-e 

 from Sinai. 



This being the typical locality of A. rnssatns, the live ones are 

 topotypes, and they differ in several particulars from those found 



* P.Z.S. 1911, r-5- t P-Z-S. 1909, p. 



795. 



