Dr. N. Sevcrtzoft* un the ManimaUi of Turkestan. 55 



must be sought tor. 1 will also add tliat ('. murinus Ls suine- 

 wliat darker tlian A. in-rnlis. As regards the gcograpliieal 

 distrihiitiun ot" this iKiiuster, only tiic two abdve-inentioned 

 localities arc known, as 1 have not since tiien met with any 

 others. 



In the spring of 1864 I met with many A. arvalis on the 

 Irtish and Ishini. I examined them in search of cheek- 

 pouches ; but there were no C. murinus among them.] 



48. Meriones tamaricinus. 



Has been nn't with by me about the Lower Syr-Darja and 

 Lake Aral in the low plains, where it is a resident. 



49. Meriones meridianus. 

 Range similar to that of the preceding species. 



50. Meriones opimus. 



A very common resident throughout Turkestan, except the 

 south-western parts. It keeps, liowever, always at low 

 elevations. 



5L Meriones [Rhomboviys) colliumj n. sp. 



Is an intermediate form between M. ojiimus and M. tama- 

 rici)ius, having the size and coloration of the latter and the 

 tail-tuft of the former ; but it is differently coloured from 

 either, and somewhat smaller. Here I give the comparative 

 diagnoses : — 



M. coUium. Supra rufesccns, nigro irroratus, apicibus pilium nigris, 

 subtus albus ; cauda corpori concolor, fioccosa, bicolor, pilis ru- 

 fescentibus et nigris intermixtis ; flocco etiam bicolori, fuliginoso et 

 canesceut* ; dentes incisoi-es supra unisulcati. 



M. ojiimus. Supra pallide et sordide fulvescens, fuliginoso irroratus ; 

 Cauda prfctcr floccura nigrum uaicolor, iutensius fulva ; dentes inci- 

 sores bisulcati. 



JiM, Jyhkus). Ut M. opimus, sed incisoribus unisulcatis. 



AI. tamarlcinus. Ut M. coUium, sed flocco caudae pei-parvo, psene 

 distincto, cauda unicolori fuhginosa. 



M. collium has the black tail-tuft surrounded by a pale grey 

 margin ; the hair of the latter is just as long as the black-tuft 

 hair. Length about 7-8 inches, tail Gy- 7 inches. C)btained 

 on the lower spurs of the Scmirechinsk-Alatau, between Koksa 

 and Hey, and also on the Karatau Mountains. In the latter 

 locality I obtained in .Tune 1867 a young specimen, which 



