The genus Nasalis is hardly separable from the genus Semnopithecus. It is a Bornean animal, and is distinguished by a comical long nose, which not only suggests, but goes beyond, the aquiline nose of the human species. It is no doubt on this account that the Borneans, unconsciously imitating our habit of comparing "natives" in general to Monkeys, call it by a name which signifies "white man." Rhinopithecus has also a long, but a more definitely upturned nose.
Fossil Monkeys.—Several of the existing genera of Old-World Apes are also known to have existed in past times; in some cases their past distribution indicates a greater range. Thus Macacus is now represented—and that doubtfully—in Europe by the Barbary Ape alone. But from Montpellier have been unearthed the remains of M. priscus, from Pliocene beds. The Asiatic Semnopithecus is known to have lived during the Pliocene period; its remains are discovered in France and Italy, as well as in Asia. In addition to these existing forms, a number of totally extinct Old-World genera are known. The rich formation at Pikermi near Athens has produced Mesopithecus pentelici; this Monkey has a skull which recalls that of Semnopithecus, while the stout limbs are rather Macaque-like. As is the case with many living Catarrhines, the males have stronger canines. The animal had a long tail.
An analogous annectent character is shown by the Italian fossil, Oreopithecus bambolii. This animal was referred by one palaeontologist to the Man-like Apes, by another to the Cercopithecidae. It suggests a common ancestral form, and is Middle Miocene in horizon.
Just as there are no Platyrrhine Apes in the Old World so there are no Catarrhines met with in a fossil condition in the New World; the two great divisions of the Apes were as distinct in the past, so far as we know, as they are now—a strong argument in favour of those who would derive them from two sources. The
existing genera, Cebus, Mycetes, and Callithrix, now living in South America, are also known in a fossil state. The extinct genus Homunculus is known from the Tertiary strata of Patagonia, and an apparently allied form is Anthropops. These creatures, however, are at present far from exhaustively known.
Fam. 2. Simiidae.—The Anthropoid, or Man-like Apes,[[420]] may be separated from the lower Apes as a group, Simiae, or perhaps better, on account of the after all slender points of difference, a family Simiidae, which has the following distinctive characters.
Though arboreal creatures for the most part, these Apes, when they come to the ground, progress in at least a semi-erect fashion. Moreover, when they, as is usually the case, put their hands upon the ground to aid in walking, they do not rest as do the lower Apes upon the flat of the hand, but upon the back of the fingers. None of the Anthropoids has a tail, or cheek pouches. Ischial callosities are only seen in the Gibbons. There is commonly a laryngeal pouch, which is of large size, and aids in the production of the generally loud voice of these creatures. The hair is rather more scanty than in the Cercopithecidae, which is an approach to Man. The placenta differs in detail from that of the lower Apes, and is exactly like that of Man. These Apes show as further differences from the underlying Cercopithecidae, the greater length of the arms as compared with the legs, and the presence of a vermiform appendix to the caecum. In the latter but not the former character they agree with Man, whom we shall place in a separate family, Hominidae. The Anthropoid Apes are entirely Old World and intratropical in range at the present time.
The Gibbons, genus Hylobates, stand quite at the base of the series of existing Anthropoid Apes. They are the smallest and the most purely tree-frequenting of all the members of that group. Connected with this habit is the structural peculiarity that their arms are proportionately longer than in the other Anthropoids. The affinity of the Gibbons to the Catarrhines is proved by the presence of distinct but small ischial callosities. The arms are so long that when walking upright the hands reach the ground. The hallux is well developed. The ribs are thirteen pairs. In the skull the chief noteworthy character as
compared with other Anthropoids is the fact of the large size of the canines, which are of equal or nearly equal size in the two sexes. The molars on the other hand have been particularly compared to those of Man. The brain is simpler than in the higher forms. But it is not clear that this may not be a case of diminished complexity of convolution going hand in hand with smallness of size.
