The pre-maxillæ are very much reduced, so that the teeth they usually carry are generally wanting. The bony palate is short, its hind margin extending back only to the middle of the median molar; its anterior foramina are small; and it differs from that of _Microcebus_ and _Chirogale_ in having its posterior perforations small. The angle of the lower jaw is produced downwards and backwards. The mastoid portion of the ear-capsules (periotic bones) as well as the squamosal are markedly {85}enlarged and swollen, in this respect differing from the skulls of _Lemur_ and _Hapalemur_. The ridges in the temporal bone unite into a frontal (sagittal) ridge, and the space between the orbits is depressed; a depression is also present on the cheek in front of the lachrymal foramen. The foot is slightly elongated by the lengthening of the _naviculare_ bone of the ankle (_tarsus_), the thin bones of which are short. In the wrist (_carpus_) there is no _os centrale_ or central bone, which is otherwise invariably present in the Primates, except in Man, the Chimpanzees, the Gentle-Lemurs, and the Endrina. The Sportive-Lemurs are confined to Madagascar and are nocturnal and arboreal creatures, feeding on leaves and fruits. In Group A (the larger species) are included: 1, The Weasel-like Lemur (_L. mustelinus_); 2, the Red-tailed Sportive-Lemur (_L. ruficaudatus_); 3, Edwards' Sportive-Lemur (_L. edwardsi_); and 4, the Small-toothed Sportive-Lemur (_L. microdon_). Group B (consisting of the smaller species) comprises: 1, The Round-headed Sportive-Lemur (_L. globiceps_); 2, Grandidier's Sportive-Lemur (_L. grandidieri_); and 3, the White-footed Sportive-Lemur (_L. leucopus_). With the exception of the two first-named species, all the others are here made known for the first time by Dr. Forsyth Major. Very little is recorded of the habits of these animals. They are so rare that at present the various species are known from a few skins or alcoholic specimens in European museums. They are said to be inhabitants only of the forest-country, nocturnal in their habits, sleeping coiled up in some retreat all day, but issuing forth at night, at which time they are very agile in their movements. {86}SECTION A. (SPECIES MAJORES.) I. THE WEASEL-LIKE SPORTIVE-LEMUR. LEPIDOLEMUR MUSTELINUS. _Lepilemur mustelinus_, Is. Geoffr., Cat. Méth. Primates, p. 76 (1851); Schl. et Pollen, Faun. Madag., Mammif., p. 10, pls. 4, 6, fig. 3; Schl., Mus. P. B., vii., p. 317 (1876). _Lepilemur dorsalis_, Gray, Cat. Monkeys, Brit. Mus. App., p. 135 (1870). CHARACTERS.--Fur soft and woolly; ears rounded, naked excepting at the base behind; muzzle elongated. Above, reddish-grey. Face and cheeks grey; throat white; under side of body and inner side of limbs, pale grey; tail short-haired, the posterior third dark brown. Length of body, 14 inches; and tail 10 inches.