Page:Encyclopædia Britannica, Ninth Edition, v. 14.djvu/460

 440 L E M U K LEMUR, a term applied by Linnaeus to a group of mammals, and suggested by the nocturnal habits and strange ghost-like appearance of some of its members. As they had previously no vernacular appellation in English, it has been generally adopted, and is now completely anglicized, making &quot; lemurs &quot; in the plural. The French call them Makis, the Germans Halbaffen, in allusion to their forming, in appearance at least, a transition from monkeys to ordinary quadrupeds. For the same reason they are called Prosimix by some systematic writers. When the name was bestowed by Linneeus, only five species were known, of which one, L. volans, Linn., Galeopithecus volans of modern writers, is now removed by common consent from the group. Notwithstanding the discovery of many new and curious forms, the lemurs remain a very natural and circumscribed division of the animal kingdom, though no longer considered a single genus, but divided up into many genera and even families. The Lemurs, or Lemuroid animals as they ought more properly to be called, were formerly associated with the monkeys in the Linnaean order Primates, and afterwards in the Quadriimana of Cuvier, forming in that order the third main division, called by Geoffroy St Hilaire Strepsirhina, on account of the twisted form of the external nostrils, a division equivalent in value to the Catarhina or Old World and the Platyrhina or New World monkeys. As more complete knowledge of their organization has been gradually attained, the interval which separates them structurally from the monkeys has become continually more evident, and they are now considered either as a distinct suborder of the Primates, or even as forming an order apart, without any very near affinities with the animals with which they have hitherto been so closely associated. 1 The existing species are not numerous, and do not diverge widely in their organization or habits, being all of small or moderate size, all adapted to an arboreal life, climbing with ease, and, as they find their living, which consists of fruits, leaves, birds eggs, small birds, reptiles, and insects, among the branches of the trees, thsy rarely have occasion to descend to the ground. None are aquatic, and none burrow in the earth. Many of the species, but by no means all, are nocturnal in their habits, spending the day in sleeping in holes, or rolled up in a ball, perched on a horizontal branch, or in the fork of a tree, and seeking their food by night. Their geographical distribution is very peculiar; by far the larger proportion of species, including all those to which the term &quot;lemur&quot; is now especially restricted, are exclusively inhabitants of Madagascar, where they are so abundant and widely distributed that it is said by M. Grandidier, who has contributed more than any other traveller to enrich our knowledge of the structure and manners of these animals, that there is not a little wood in the whole island in which some of them cannot be found. From Madagascar as a centre a few species less typical in character extend through the African continent westward as far as Senegambia, and others are found in the Oriental region as far east as the Philippine Islands and Celebes. The following are the essential anatomical characters common to the whole group : Teeth heterodont, or divided by their form into incisors, canines, and molars, and diphyodont, or consisting of a first and second set. Molars multicuspidate. Skull with 1 For the arguments in favour of the latter view see Alphonse Milne-Edwards, &quot;Observations sur quelques points de I embryologie des Lemuriens et sur les affinites zoologiques de ces animaux,&quot; in the Ann. des Sciences Nat., October 1871 ; and P. Gervais, &quot;Encephale des Lemures,&quot; in Journ. de Zoologie, torn. i. p. 7. For those for retaining them among the Primates, see Mivart, &quot; On Lepilemur and Chirogaleus, and on the Zoological Rank of the Lemuroidea,&quot; in Proc. Zool. Soe., 1873, p. 484. complete bony margin to the orbits, which communicate freely (except in Tarsius) with the temporal fossae. Lacrymal foramen outside the margin of the orbit. Clavicles well developed. Radius and ulna distinct. Scaphoid, lunar, and central bones of the carpus almost always separate. Five digits on the manus and pes, though the index of th manus may be rudimentary. Pollex (or thumb) and hallux (or great toe) always well developed the latter especially large, opposable to the other digits, and with a flat nail. The index or second digit of the pes always terminating in a long pointed claw. The fingers and toes generally not tapering towards their extremities, but (except in Chiromys} dilated, flattened, and rounded at the tips. Cerebral hemispheres not completely overlapping the cerebellum, and but little convoluted. Stomach simple. Caecum always present, generally large. The middle or transverse portion of the colon almost always folded or convoluted on itself. Uterus bicornuate. Placenta non-deciduate, diffused or bell-shaped the whole of the chorion, except the cephalic pole, being covered with villosities. Allantois of great size. In subdividing the group for the purpose of a more detailed description of the different animals of which it is composed, it must first be noted that there are two very aberrant forms, each represented by a single species (1) the little Tarsius of the Indian archipelago, and (2) the singular Chiromys or aye-aye, which, though an inhabitant of the headquarters of the order, Madagascar, and living in the same forests and under the same external conditions as the most typical lemurs, exhibits a most remarkable specia lization in the structure of its limbs and teeth, the latter being modified so as to resemble, at least superficially, those of the rodents, an order in which it was once placed. The differences between these two forms and the remaining lemurs is so great that the whole order naturally divides itself into three families, the first of which may be again divided into four subfamilies, which with the genera they contain may be thus arranged : Family 1. Lemuridae. Gcncrfl - ( Indris. Subfamily 1. Indrisinaz &amp;lt; Propitliecus. ( Avahis. ! Lemur. Hapalemur. Lepilemur. 3. Galaginse. Chirogalevs. Galago. i Loris. ,, 4. Lorisinss &amp;lt; Nycticebus. ( Perodicticus. Family 2. Tarsiidas Tarsius. 3. Chiromyidse Chiromys. Family LEMURiD.fi. Upper incisors two on each side, small and separated by an in terval in the middle line. Upper canines large, conical, compressed, and pointed. Premolars two or three, molars three on each side above and below, with numerous, more or less pointed, cusps. In the front of the lower jaw are on each side two or three closely approximated, long, slender teeth lying almost horizontally and projecting forwards. These are generally considered to represent the incisors and canines, but there is some doubt about their homologies, and they may be all considered as incisors, the canine being absent. The first lower premolar larger than those behind it, and shaped like a canine. The orbit and temporal fossa widely continuous beneath the bar of bone (formed by the frontal and malar) constituting the posterior boundary of the former cavity. The fibula well developed and distinct from the tibia. All the digits of both feet (except the second of the hind foot) with flat nails, and corresponding form of ungual phalanges. I. Subfamily Indrisinae. The dentition of the adult consists of thirty teeth, usually expressed by the formula i, c, p, mf ; but, as indicated above, they may be i, c, p%, m%. In the