small Mammals from Djarleut. oil 



fusciceps, of which I originally described tins Ellohius as a 

 subspecies. 



In E. fuscipes the lambdoid ridge is continuous and well 

 defined right across the skull, bowed forwards in its middle 

 third. In ursulus it is practically obsolete for this middle 

 third, the crown and occipital areas passing almost smoothly 

 into one another. In ursulus, also, m^ tends to be rather 

 simpler than in fusciceps. 



29. Allactaga rilckheih', sp. n. 



Six. 



A. mongoUca group. 



Size about as in A. suschkini and monjoUca, larger than 

 in saltator. Colour rather paler than in our examples 

 of saltator. Crown distinctly greyer than back. Ears 

 proportionally long, apparently about as long as in susch- 

 kini. Hands and feet pure white ; central sole-pad un- 

 covered in all the specimens, covered with hair in all the 

 available examples of mongoUca and saltator. Tail buffy 

 above, white below, with well-marked white ring before the 

 black one, black ring varying from about 45 to 55 mm., 

 measured from its commencement in the middle line to the 

 tips of the longest hairs; white terminal tufts short, only 

 about 30-35 mm. measured in the same way. 



Skull larger than in saltator, with shorter muzzle than in 

 mongoUca. 



Dimensions of the type : — 



Head and body 150 mm. ; tail 220; hind foot (s. u.) 76 ; 

 ear 49. 



Skull : greatest length, occiput to giiathion, 39 ; condylo- 

 incisive length 38'3 ; zygomatic breadth 25*8 ; nasals 14*3 x 

 6; interorbital breadth 10*8 ; breadth of brain-case 19; pala- 

 tilar length 22*5 ; palatal foramina 8*7 ; nsolar series (exclu- 

 sive of premolar) 6*3. 



Type. Adult female. B.M. no. 14. o. 10. 203. Original 

 number 247. Collected 6th April, 191 3. 



" On banks of River Uszek." 



This jerboa is probably most nearly allied to A. suschkini, 

 from north of the Aral Sea, but is distinguished by having 

 a well-marked white ring before the black one of the tail, no 

 trace of such a ring being present in suschkini, and, on the 

 other hand, by its very much shorter white terminal tuft. 

 From A. saltator it is distinguished by its larger size and 

 the more open condition of the foot-pads. Mr Hollister's 

 A. grisescens, coming not only from the general region, but 



