518 



PROCEEDINGS OF THE NATIONAL AJUSEUM. 



VOL. 45. 



Measurements of selected adult specimens of Microtus (Stenocranius) from the Altai 



Mountains. 



ALTICOLA (PLATYCRANIUS) STRELZOVI (Kastschenko). 



1899. Microtus strelzovt Kastschenko, Pes. AjixaficKoii Sooji. 3Kcn. 1898. 



[Results Altai Zool. Exp.] Tomsk, p. 50, pi. 2, figs. 2, 3. 

 1901. Microtus {Platycranius) strelzowi'KK&TS.cs.'Ej^'S.o, Ann. Mus. Zool. Acad. Sci. 



St.-P6tersbourg, vol. 6, p. 201. 



Seventy-two specimens from the frontier range in the Tchegan- 

 Burgazi Pass, July 1-26. This mouse is by far the most abundant 

 mammal in the rocky parts of the desert mountains. At least a 

 hundred specimens were caught in addition to the number preserved. 

 Our experience with the species exactly agrees with Kastschenko's 

 account of its local habitat, and we caught the animal only among 

 the loose rocks. So closely is it confined to rocky cliff sides that, 

 although exceedingly abundant in such places, traps set only a few 

 feet out in the grassy creek bottoms, or in the alps above the rocks, 

 almost invariably failed to catch specimens. The fully adult exam- 

 ples, when freshly caught and in full coat, are strikingly handsome 

 mammals. Most of our specimens were taken at about 8,500 feet 

 elevation, and although a few were captured up to a thousand feet 

 higher, the lower cliffs near the stream beds seemed to be the normal 

 home. At Tapucha we did not catch this mouse, doubtless because 

 we trapped almost entirely in the forest and alps. The type-locality 

 is Lake Tenga, only about 25 versts south of Tapucha, but at a much 

 lower elevation and in' a much more open country. 



The subgenus Platycranius, described by Kastschenko as a sub- 

 genus of Microtus, is clearly an aberrant Alticola, as surmised by 

 Miller.^ The palate, enamel pattern, mammary and plantar tubercle 



> Ann. and Mag. Nat. Hist., ser. 8, vol, 1, p. 97, January, 1908. 



