Thian Shan Ibex 283 



whitish at the base — purest where the extremities are merely tinged 

 brown, and less so where they are dark." 



In the white on the lower part of the hind -legs, as well as in the 

 whitish under -parts, these specimens agree with the British Museum 

 examples from the Thian Shan and Altai, but differ by the much darker 

 upper-parts, on which the whitish saddle alone accords with the general 

 coloration of the latter. They agree, however, in their general darkness 

 with Dr. Radde's description of an ibex in the winter pelage from the 

 Sajan Mountains of Eastern Siberia, which is undoubtedly the typical 

 C. sibirica. 



The explanation of the difference appears to be as follows : — The 

 specimens described by Mr. True were shot, respectively, on the 19th and 

 2 1st of December, and were thus in the comparatively early winter pelage. 

 There is no record of the season at which the Altai and Thian Shan 

 specimens in the British Museum were killed ; but, as already said, practi- 

 cally all the ibex shot by English sportsmen in the Himalaya and Baltistan 

 are killed in the late spring. Now it is a well -ascertained fact that the 

 lighter-coloured portions of the winter pelage of the wapiti bleach con- 

 siderably as the season advances ; and it appears highly probable that a 

 similar fading takes place in the case of all the races of the present species. 

 In Mr. True's description it is stated that the hairs of many parts of the 

 body are merely tipped with brown ; and nothing is more likelv than that 

 such tips should bleach to a dirty white after exposure to the storms of 

 winter. Dr. Scully's explanation that the dark individuals are old males 

 in the winter pelage, although true to a certain extent, is insufficient, 

 because the majority ot specimens shot by English sportsmen are likewise 

 old males in the winter pelage, and yet are light-coloured. 



Distribution. — From the Altai and Sajan ranges through the Thian Shan 

 to the Trans-Indus districts of Gilgit and Baltistan, not extending east of 

 Lake Baikal. The ibex obtained by the English Boundary Commission 



