a state of constant activity, playing and running about in search of food in the neighbourhood of their dwellings. The winter they pass in a state of torpidity, in a comfortable chamber lined with soft herbage, and protected from the outside cold by the closure of the main passage leading into their abode. For a time after their retirement for the winter they continue active in their domicile, and feed upon the stores of food which they have laid up during the summer; and as a preparation for their winter sleep, they become exceedingly fat during the autumn. The Marmots are the largest members of their family, and, indeed, some of them may be reckoned among the larger Rodents. The Alpine Marmot measures more than twenty inches in length, and the Bobac about fifteen inches, exclusive of the tail. [Illustration: ALPINE MARMOT.] FAMILY II.--ANOMALURIDÆ. Some curious African animals, closely resembling the Flying Squirrels, and at first regarded as belonging to that group, were formed by Mr. Waterhouse into a distinct genus, which he called _Anomalurus_, in allusion to the peculiar characters presented by their tail. This organ, which is long and well clothed with hair, although not so bushy as in the true Squirrels, has on the lower surface of its basal portion a double series of horny scales, which project from the skin, and probably serve to assist the animal in climbing upon the branches of trees. Besides this peculiarity, these animals exhibit certain other characters which have induced modern zoologists to separate them from the Squirrels as a distinct family. Thus, the post-orbital processes are wanting, or nearly so; the infra-orbital openings are large; the molar teeth are four in number on each side, above and below, nearly equal in size, and not tubercular, but with a flat surface, crossed by transverse loops of enamel; and the palate is contracted in front and deeply notched behind. In the skeleton we find sixteen pairs of ribs, whereas in the Squirrels there are only twelve or thirteen pairs; and the internal anatomy, first described by Mr. Alston, is very peculiar. The flying membrane is quite as largely developed as in the Flying Squirrels, and is in the same manner extended from the wrists to the heels, and further supported by cartilaginous spurs starting from the fore limbs; but, whilst in the Flying Squirrels this spur springs from the wrist itself, in the Anomalures it projects from the elbow, and thus produces a still greater extension of the membrane. The ears are well developed, the eyes large, and the general aspect both of head and body completely squirrel-like. Six species of this family have been described, all from the West Coast of Africa. One of them occurs in the island of Fernando Po. The species figured (_Anomalurus fulgens_) is from the Gaboon. It is a handsome little creature, of a bright reddish colour, paler below, and having a small white spot between the ears.