■454 Mr. 0. Thomas on the small Hamsters 



Tiipe. Adult female. B.M. no. 6.5.1.83. Original 

 number 2413. Collected 25th February, 1906, by A. Robert. 

 Presented by Oklfield Thomas. Seven skins and six speci- 

 mens ill spirit. 



A darker and more saturate race of C. migratorius, a 

 variation which occui's in other forms from the same district. 

 Its range eastwards into Trans-Caucasia remains to be 

 worked out, but a specimen in spirit from the Talysch Mts. 

 appears to be very similar to it. To the south, a specimen 

 from "60 miles north of Erzeroum'' [Woosnam) would 

 also seem to be referable to the same species. 



C. migratorius arenarius, Pall. 



Type-localitij. Baraba Steppes, Lower Irtish, Siberia. 

 Southwards to Lake Balkhash. 



Under surface wholly white, the hairs white to their 

 bases. 



A spirit-specimen from Mt. Bek Dauata, north of Lake 

 Balkhash ( W. Bateson), has head arid body 94 mm., tail 26, 

 hind foot 15. Its skull measures 28*5 mm. in total length, 

 its tooth-row 4"2 mm. 



The Museum only contains the above-mentioned spirit- 

 specimen, whose agreement with Pallas's description as to 

 the whiteness of the under surface leads me to assign it to 

 the true arenarius, and to consider the next form, of which 

 we have a large number of specimens, as distinct. 



C. migratorius griseiventris, Sat. 



Type-locality. R. Bis-shen-gol, Altain-nuru, Gobi Altai. 



Range. Central Asia. Samarkand and eastwards along 

 the Thian Shan, filling up the area between the ranges of 

 arenarius a,ndfulvus. 



Size averaging larger and teeth heavier than in the 

 western forms. Fur longer — hairs of back 10 mm. or more. 

 General colour above pale grey, more or less strongly 

 suifused with buffy or fulvous. Under surface with the 

 hairs snowy white to the bases on throat and inguinal 

 region, but broadly slaty at base on the belly. 



A male from Djarkent measures : — Head and body 

 120 mm. ; tail 27 ; hind foot 16. Skull : greatest length 

 30; upper tooth-row 4'5. 



Of this form the Musevxm possesses a fine series from 

 Djarkent, collected by W. Kiickbeil, besides specimens 

 from Samarkand, Dzungaria, Hami and elsewhere in the 

 Carrutliers collection. It diifers from C. m. arenarius by 

 the presence of broad slaty bases on the belly hairs. 



