70 MR. O. THOMAS ON THE MAMMALS OF [Jail. 19, 



S, CANICEPS TYPICUS. 



(S. chrysonotus, Bly.) 



A seasonal change. In summer all grey, in winter back brilliant 

 orange-yellow. 

 N. Tenasserim. 



S. CANICEPS CONCOLOR, Bly. 



No seasonal change. Sides of neck and of belly rufous, dull in 

 northern, brilliant in southern specimens. 



S. Tenasserim to Malacca. 



The alternatives, under the binomial system, of either splitting 

 this species into five, or of lumping all the varieties under one head, 

 are both too unsatisfactory for adoption. For the first there are far 

 too many intermediate specimens and gradations, and for the second 

 the differences between fully ornamented specimens of S. phayrei, of 

 8. concolor, and of breeding specimens of iS. caniceps typicus, are 

 infinitely too striking. 



The manner and dates of the seasonal change in <S^. caniceps typicus 

 are well illustrated by the series from iS". Tenasserim. In October the 

 yellow begins to appear in small patches on the back among the 

 grizzled grey (85. 8. 1. 184). By November the whole of the back 

 is rich yellow (85. 8. I. 182), and this remains at its best until 

 January', and then gradually becomes duller and dirtier-looking 

 {77- 10. 25. 2), until about March the summer grizzled grey hairs 

 begin again to appear in patches in the midst of the yellow (77. 10. 

 25. 1), and soon entirely supersede it. Males and females alike go 

 through this change. 



16. SciURUS ATRODORSALis, Gray. 



a. Kankaryit, near Moulmein, 10/1/77. b. Doonsa, near 



Moulmein, 8/3/77 • c, d. Lathorge, near Myawadi, 19 and 



22/\/77. e. Maitho, Thoungyeen R. 29/10/77 {Bingham). 



f,g. Mt. Nwa-la-boo, Tavoy,"5/-l/78. 



The evidence of the fine series before me, consisting of 40 speci- 



mens^ tends to show that the variation in the colour of this species is 



not so much a sign of season as of locality, southern specimens being, 



as a rule, more rufous and generally without the black back. 



It unfortunately happens, however, that nearly all the dated 

 specimens that I have seen were obtained in the winter, when the 

 black back is certainly present in most cases. However, Capt. 

 Beavan^ has described a July specimen as having a black back, and 



' Oae specimen in Mr. Blanford's collection, labelled as from Thatone, 

 January, has no yellow on its back as might be expected, and forms therefore a 

 striking exception to the general rule. It should be noticed, however, that this 

 is the very specimen of which Mr. Blanford wrote in 1878 (J. A. S. B. xlvii. 

 p. 162), " The skin so precisely resembles the peculiarly dark olive specimens 

 from Bankasun, that I am inclined to su.spect the label must have been changed 

 by accident." 



° Many of these were kindlv lent to me bv Mr. Blanford. 



^ P. Z. S. 1866, p. 428. 



