Page:Encyclopædia Britannica, Ninth Edition, v. 14.djvu/463

 LEMUR 443 was the first known to science, having been brought from Senegal by Adanson, and described in 1796 by Geoffroy, who adopted the name Galago, by which it was said to be called by the natives. IV. Subfamily Lorisinae. Dental formula as in Lemurinse. In dex finger very short, sometimes rudimentary and nailless. Fore and hind limbs nearly equal in length. Tarsus not specially elon gated. Pollex and hallux diverging widely from the other digits, the hallux especially being habitually directed backwards. Tail short or quite rudimentary. Mammte two, pectoral. A small group of very peculiar animals, of essentially nocturnal habits, and remarkable for the slowness of their movements. They are completely arboreal, their limbs being formed only for climbing and clinging to branches, not for jumping or running. They have rounded heads, very large eyes, short ears, and thick, short, soft fur. They feed, not only on vegetable substances, but, like many of the Lemitridae, also on insects, eggs, and birds, which they steal upon while roosting at night. None of the species are found in Madagascar. One of the greatest anatomical peculiarities of these animals is the breaking up of the large arterial trunks of the limbs into numerous small parallel branches, constituting a rcte mirabilc, which is found also in the true sloths, with which the loris are sometimes confounded on account of the slowness of their move ments. The animals of this group are usually divided into four genera, though the characters by which they are separated are very trivial. There are more properly two natural divisions. A. Characterized by the index finger being small, but having the complete number of phalanges, and by their Asiatic habitat. These form the genus Loris of Geoft roy St Hilaire (1796), Stcnops of Illiger (1811), but they were in 1812 divided by Geoffroy into two genera, Xycticebus and Loris, a division which has been accepted by most modern zoologists. Genus Nycticebus, Geoff. First upper incisor larger than the second, which is often early deciduous. Inner margin of the orbits separated from each other by a narrow flat space. Nasal and pre- maxillary bones projecting but very slightly in front of the maxillte. Body and limbs stout. No tail. Vertebra : C7, D17, 1,6, S3, 012. The species are N. tardigradus, the common slow lemur or loris, of the Malay countries, Sumatra, and Borneo; N. javanicus, of Java ; and A 7 &quot;, cincrcus (fig. 5), ofSiam and Cochin China. The FIG. 5. Grey Loris (Xycticebus clnereus). From A. Milne-Edwards, N. Archives du Mus um, tome iii. pi. 3. habits of all are much alike. They lead a solitary life in the recesses of large forests, chiefly in mountainous districts, where they sleep during the day in holes or fissures of large trees, rolled up into a ball, with the head between the hind legs. On the approach of evening they awake ; and during the night they ramble among the branches of trees, slowly and quietly, in search of their food, which consists of tender leaves and fruit, small birds, insects, and mice. &quot;Vhen in quest of living prey, they move noiselessly till quite close, and then suddenly seize it with one of their hands. The female produces but one young one at a time. L. tardigradus was placed by Linnaeus at the head of the list of species of his genus Lemur, and its habits doubtless suggested the generic name which was trans ferred by Gcolfroy to the less nocturnal and spectre-like Madagascar members of the group. 1 Genus Loris, Geoff. Upper incisors very small and equal. Orbits very large, and only separated in the middle line above by a thin vertical plate of bone. Nasals and premaxill;e produced for wards considerably beyond the anterior limits of the maxillae, and supporting a pointed nose. Body and limbs slender. No external tail. Vertebra : C7, D14. L9, S3, C6. 1 For the anatomy of this genus, sec J. L. C. Sliroeder van der Kolk and W. Vrolik, &quot;Recherchea d Anatomie cnmpare e sur le genre Stciwps d llliger,&quot; in Bijdragen tot Je Dierttmde, part i., Amsterdam, 1848-o4. One species, L. gracili-*, the slender loris of Ceylon, a very strange- looking creature, about the size of a squirrel, of a yellowish-brown colour, with large, prominent eyes, pointed nose, long thin body, long, angularly bent, slender limbs, and no tail. Its habits are like those of the rest of the group. B. Index finger reduced to a mere tubercle without nail. Both the known species are from West Africa. Genus Perodicticus, Bennett. A short tail, about a third of the length of the trunk. Two or three of the anterior dorsal vertebrae have very long slender spinous processes which in the living animal project beyond the general level of the skin, forming distinct coni cal prominences, covered only by an exceedingly thin and naked integument. P. potto (Lemur potto, Gmelin), the potto, is one of the oldest known members of the lemuroid group, having been de scribed in 1705 by Bosnian, who met with it in his voyage to Guinea. It was, however, lost sight of until 1825, when it was re discovered in Sierra Leone and fully described by Bennett in the Proceedings of the Zoological Society, part i. ,1830-31, under the name of Perodicticus Geoffroy i. Bennett s generic name has been retained, but the specific name bestowed by Gmelin, adopted from Bosnian, has been restored. It is also found in the Gaboon. It is strictly nocturnal, and slower in its movements even than Nycticebus tardi gradus, which otherwise it much resembles in its habits. 2 A second species, the awantibo (P. calabarcnsis, Smith), rather smaller and more delicately made, with smaller hands and feet, and rudimentary tail, constitutes the genus Arctocebus, Gray. It is found at Old Calabar, and is very rare, only a few individuals having as yet been met with. Its anatomy has been described by Professor Huxley in ilieProc. Zool. Soc., 1864, p. 314. Vertebra: C7, D15, L7, S3, C9. Family TAESIIDJE. Dentition, if, c, p%, mf = f, total 34. The first upper incisor large, and in contact with its fellow of the opposite side. Canine of moderate size. Molars, with numerous pointed cusps. Lower canine semi-erect, its apex diverging from that of the single incisor. First lower premolar smaller than those behind it. Orbit to a large extent separated from the temporal fossa by a bony partition. Fibula slender, with its lower half confluent with the tibia. Second and third digits of the hind foot with compressed claws ; all the other digits of both feet with flat nails. Calcaneum and navicular bone of the foot elongated as in the chirogales and galagos, but to a still greater extent. Colon short and not folded. Vertebra : C7, D13, L6, S3, C27. This family contains the single genus Tarsius, Storr, of which but one species is known, T. spectrum, the tarsier, a very singular little animal, rather smaller than an English squirrel, with very large eyes and ears, a long thin tail, tufted at the end, and immensely elon gated tarsal portion of the foot, in allusion to which its generic name was given to it. It inhabits the forests of many of the islands of the Indo-Malayan archipelago, Sumatra, Borneo, Celebes, and some of the Philippines, feeds chiefly on insects and lizards, sleeps during the day, but is tolerably active at night, moving chiefly by jumping from place to place, an action for which the structure of its hind legs, which present a curious resemblance to those of a frog, seems particularly well adapted. It is rare, not more than two being generally found together, and only brings forth one young at a time. 3 Family CHIROMYID.E. Dentition of adult, i-, c%, p^, ?nf = f, total 18. Incisors very large, compressed, curved, with persistent pulps and enamel only in front as in rodents. Teeth of molar series with flat, very indistinctly tuberculated crowns. In the young, the first set of teeth more resemble those of the normal lemurs, being i%, cb ??if, all very small. Orbit surrounded by a ring of bone posteriorly, beneath which it communicates freely with the temporal fossa. Fibula well-developed and distinct from the tibia. All the digits of both feet with pointed rather compressed claws, except the hallux, which has a flattened nail. Middle digit of the hand excessively attenuated. Vertebra : C7, D12, L6, S3, C27. This family, like the last, is formed for the reception of a single genus, Chiromys, Cuvier, 4 containingone species, C. madcgascariensis (Gmelin), the aye-aye, an animal about the size of a cat, with abroad rounded head, short face, and large and naked ears. It has very large hands and long thin fingers with pointed claws, one of which (the middle or third) is remarkable for its extreme slenderness. The foot resembles that of the other lemurs in its large opposable hallux, with a. flat nail, but all the other toes have pointed com- 2 Van der Hoeven ami Van Campen, &quot; Ontleedkundigonderzoek van der Potto ran Bosnian,&quot; in Verh. Kong. Akail. ran Wetenschapprn, Amsterdam, 1859. 3 H. Burmcister, Btitrii je zitr nahreren Kenntniss der Gattung Tarsius, Berlin, 1846. 4 It was first named Daubentonia by Geoffroy; but this name was withdrawn by its author in favour of Chiromt/i, as it had been previously Riven to a genus in the vegetable kingdom. It ought not, therefore, to be revived, as has been done by some modern authors.