56 Br. N. Severtzo^ on the Mammals of Turkestan. 



differs from the adult only by its smaller size and the propor- 

 tionally smaller tail-tuft. 



M. opimus, which has been collected in great numbers on 

 the Iley, near Hodgent, and lower down at the Syr-Darja, 

 has sometimes a sharply marked black line running from the 

 tail-tuft along the upperside of the tail almost to its root ; this 

 line, however, is very variable in its length. 



According to the characters and distribution it appears to 

 me that M. coUium is the general origin of the steppe gerbiUes 

 {M. tamaricinus and M. opimus), which inhabit the bottom ol 

 what, geologically speaking, was at no distant period a lake ; 

 as well as of M. lyhicus, which, in its dentition, comes closer 

 to M. collium than is M. opimus, and perhaps has been driven 

 out by the latter to the south-west. 



But up to the present time the limits of the ranges ot M. 

 opimus and M. lyUcus are unknown ; they probably meet 

 in the deserts of Persia or Syiia *. 



52. Dipus jaculus. 



Has been found by me almost all over Turkestan, being not 

 rare in the eastern parts and very common m the north- 

 western districts, where it appears to be a resident at an alti- 

 tude of from 1000 to 4000 feet above the sea, *. e. m the cul- 

 tivated districts. 



53. Dipus acontion. 



54. Dipus sagitta, var. telum. 



55. Dipus lagopus. 



56. Dipus platyurus. 



These fom- species have been observed in the low plains 

 at the mouth of the Syr-Darja, at the sources of the Aris, and 

 about Lake Aral as residents. 



57. Elhhius talpinus, var. rufescens. 

 Has been met with by me throughout the east and north of 



* rin his list Dr. Severtzoflf orif?inally named this species Meriones mm- 

 tanm; but having discovered that this name was P^-^occupied by Sir 

 Andrew Smith for a South-African species, he renamed it (at p. bd) 

 Meriones collium. — F. C. C.J . t?„„4.„„„ 



[Mr Blanford describes an interesting new species kom Eastern 

 Turkestan, which he names GerhiUus cnjptorhmushora ih^ r^ra^xk^h}^ 

 semicircular flap which covers the nostrils (Journ. Asiat. Soc. Beng. xliv. 

 p. 108).— E. K. A.] 



