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Show 1871.] DR. J. ANDERSON ON NEW SQUIRRELS. 141 inquiry. In connexion with this subject it should also be borne in mind that the coloration of the young of some species of Squirrel is \ery different from that of their parents, so that we must first eliminate all the changes which are due to this cause before we can determine to what extent the variations of colour in this obscure group are influenced by the rutting-period or in any way affected by it. If we are ever to arrive at a correct understanding of the causes which produce the periodic variations of colour which we cannot but allow do occur among the most puzzling group of rodents, it will be only by painstaking observation of the species in their native forests and by the accurate recording of the phenomena as they appear. I would appeal to all naturalists in India, Burmah, and the Malayan peninsula, who have the opportunity, to give this neglected group a little of their attention ; and I would suggest that the first step should be to ascertain how many well-marked species occur in a district, and second to observe if the sexes are alike in colour, and to note the changes, if any, to which they are subject, verifying each by a series of specimens of both sexes shot throughout the year. It seems very probable that as our knowledge of this group advances, the present number of Southern Asiatic forms will be greatly reduced. S. gordoni belongs to what appears to be a distinct group of Squirrels, distinguished from the rest of the genus by grizzled or plain lineation of different colours of the ventral aspect. Blyth's species, S. griseopectus, was the first which showed this peculiarity of ventral lineation. He describes it as having " the throat and breast, and the median line of the belly, of a deep grizzled ash-colour, without a tinge of rufous, and much of the same hue as the crown and exterior of the limbs and feet." The locality of this Squirrel was unknown to him ; but there are two specimens in the British Museum from China correctly referred to it by Dr. Gray, who, however, in his Synopsis of the Asiastic Squirrels, makes no reference to the mesial lineation of the belly, which is well marked in the specimens from which his description is taken. The Squirrel which I have next to describe has no less than five distinct stripes along the belly ; and it is probable that future research will not furnish a more intensely ventrally lineated form than it, although it is likely that the gap that exists between S. griseopectus and S. gordoni and this five-lined form, S. quinquestriatus, will be filled up by species having three and four ventral lines. The lineated grizzled Squirrels of Southern and Eastern Asia may now be referred to three distinct groups,-the first, the dorsally lineated forms, illustrated by such species as S. palmarum, S. berdmorii, S. penicillatus, S. sublineatus, S. layardii, S. macclellandi, and <$. insignis; the second, the laterally lineated Squirrels, including S. rafflesii, S. sarawakensis, S. rufogularis, S. rufoniger, S. atricapillus, S. vittatus, S. nigrovittatus, and S. plantani; and the third, the ventrally lineated forms, S. griseopectus, S. gordoni, and S. quinquestriatus. The dorsally lineated Squirrels through S. macclellandi are connected with the aberrant form, S. melanotis, which is characterized by the banding of the sides of the head. |