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Show 70 MR. O. THOMAS ON THE MAMMALS OF [Jan. 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 S. concolor, and of breeding specimens of S. caniceps typicus, infinitely too striking. The manner and dates of the seasonal change in S. caniceps typicus are well illustrated by the series from N. 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. 1. 182), and this remains at its best until January1, 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 Mvawadi, 19 and 22/1/77. e. Maitho, Thoungyeen R. 29/10/77 (Bingham). f g. Mt. Nwa-la-boo, Tavoy,5/4/78. The evidence of the fine series before me, consisting of 40 specimens2, 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. Beavan3 has described a July specimen as having a black back, and 1 One 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 Bankasuu, that I am inclined to suspect the label must have been changed by accident." 2 Many of these were kindly lent to m e bv Mr. Blanford. 3 P. Z. S. 1866, p. 428. |