CHEPROMYS, one of the generic names given the Aye-Aye (which must not be confounded with the Ai, or Sloth [BR...ovens], from which it very strongly differs in organisation), an animal discovered by Sonnerat at Madagascar, and described by him in the second volume of his Voyage aux Irides.' The name Aye-Aye it appears is an exclamation of the motives ; and it is conjectured that it was given to this animal in consequence of a supposed resemblance to its cry. Sonnini, who formed the genus, censures Gmelin for denominating it Seisms ,Vadayas.eariensis (Madagascar Squirrel), because a quadruped of the latter genus really exists in Madagascar. Cuvier places the form next to the Flying Squirrels, Polatouchts (Pteronly3), and immediately before the Rats (Mus, Linn.), remarking that the lower incisors are much more compressed, and especially more extended from before backwards, than those of the squirrels, and resemble ploughshares (secs de charrue). The feet, he adds, have all five toes, of which four of those on each anterior extremity are elongated, the middle toe tieing much more slender than the others ; in the hind feet, the great toe is opposeable to the others, so that in this respect the animal is among the Rodents what the Opossums (Sarigues) are among the Carnassiers. The structiu-e of the head, ho continues, is very different from that of the other Rodents, and has more relation to the Quadrurnana.
— Dental formula : incisors, 2 ; molars, g - 4-4 3-3 ' Sonnerat says that the Aye-Aye, which is found chiefly if not exclusively on the western part of the island, does not approach any genie", but that it leans towards the Maki, the Squirrel, and the Ape.
Its large and flat ears, he observes, resemble much those of a bat ; and states that its principal character, and a very singular one it is,' is the middle toe or finger of the fore foot, the two last joints of which are very long, slender, and denuded of hair. This member, he adds,'
is useful to it in drawing worms out of holes in the trees, and that it seems also to be of service in bolding on to the branches of trees. He says that it appears to be a subterranean animal, and does not see during the day, and that its eye resembles in colour that of the owl. He describes it as being very slothful, but good tempered, remaining always at rest, and requiring a good deal of shaking to make it move. The subject of his observations lived two months upon no other nourishment than cooked rico, and it fed itself with its two fingers like the Chinese with their chopsticks. All the time 31. Sonnerat had this animal alive, he never saw it carry its tail elevated like the squirrel. It always dragged.
Buffon describes the colour as a musk-brown mixed with black and gray-ash. On the head, round the eyes, on the body, thighs and legs, the colour was deep musk, in which nevertheless black predominated upon the back and many parts of the body and legs. The tail was entirely black : the sides of the head, the neck, the jaw, and the belly were grayish. There were woolly hairs of this gray colour below the great black or white hairs, of two or three inches long, which were on the body and legs; but the legs and thighs were of a reddish-brown. Black predominated at the approach of the feet, which were covered with small hairs of that colour. The head was like that of a squirrel, and the ears large, naked, erect, and round at their extremities, with a wide opening. It is about the size of a common hare.
This animal is the Aye-Aye Squirrel of Pennant, Shaw considered , it to be a species of Lemur, and Schrcher named it Lemur pails dadylus, a name adopted by Shaw.