Page images
PDF

discovered, which are believed to belong to this sub-order: but they form two distinct families, Lemuravidae and Limnotheridae. Other remains from the Miocene are believed to be intermediate between these and the Cebidae, a most interesting and suggestive affinity, if well founded. For the genera of these American Lemuroidea, see vol. i., p. 133.

General Remarks on the Distribution of Primates.

The most striking fact presented by this order, from our present point of view, is the strict limitation of well-marked families to definite areas. The Cebidae and Hapalidae would alone serve to mark out tropical America as the nucleus of one of the great zoological divisions of the earth. In the Eastern Hemisphere, the corresponding fact is the entire absence of the order from the Australian region, with the exception of one or two outlying forms, which have evidently transgressed the normal limits of their group. The separation of the Ethiopian and Oriental regions is, in this order, mainly indicated by the distribution of the genera, no one of which is common to the two regions. The two highest families, the Simiidae and the Semnopithecidae, are pretty equally distributed about two equatorial foci, one situated in West Africa, the other in the Malay archipelago, in Borneo or the Peninsula of Malacca;-while the third family, Cynopithecidae, ranges over the whole of both regions, and somewhat overpasses their limits. The Lemuroid group, on the other hand, offers us one of the most singular phenomena in geographical distribution. It consists of three families, the species of which are grouped into six sub-families and 13 genera. One of these families and two of the sub-families, comprising 7 genera, and no less than 30 out of the total of 50 species, are confined to the one island of Madagascar. Of the remainder, 3 genera, comprising 15 species, are spread over tropical Africa; while three other genera with 5 species, inhabit certain restricted portions of India and the Malay islands. These curious facts point unmistakably to the former existence of a large tract of land in what is now the Indian Ocean, connecting Madagascar on the one hand with Ceylon, and with the Malay countries on the other. About this same time (but perhaps not contemporaneously) Madagascar must have been connected with some portion of Southern Africa, and the whole of the country would possess no other Primates but Lemuroidea. After the Madagascar territory (very much larger than the existing island) had been separated, a connection appears to have been long maintained (probably by a northerly route) between the more equatorial portions of Asia and Africa; till those higher forms had become developed, which were afterwards differentiated into Simia, Presbytes, and Cynopithecus, on the one hand, and into Troglodytes, Colobus, and Cynocephalus, on the other. In accordance with the principle of competition so well expounded by Mr. Darwin, we can understand how, in the vast Asiatic and African area north of the Equator, with a great variety of physical conditions and the influence of a host of competing forms of life, higher types were developed than in the less extensive and long-isolated countries south of the Equator. In Madagascar, where these less complex conditions prevailed in a considerable land-area, the lowly organized Lemuroids have diverged into many specialized forms of their own peculiar type; while on the continents they have, to a great extent, become exterminated, or have maintained their existence in a few cases, in islands or in mountain ranges. In Africa the nocturnal and arboreal Galagos are adapted to a special mode of life, in which they probably have few competitors. How and when the ancestors of the Cebidae and Hapalidae entered the South American continent, it is less easy to conceive. The only rays of light we yet have on the subject are, the supposed affinities of the fossil Caenopithecus of the Swiss, and the Lemuravidae of the North American Eocene, with both Cebidae and Lemuroids, and the fact that in Miocene or Eocene times a mild climate prevailed up to the Arctic circle. The discovery of an undoubted Lemuroid in the Eocene of Europe, indicates that the great Northern Continent was probably the birthplace of this low type of mammal, and the source whence Africa and Southern Asia were peopled with them, as it was, at a later period, with the higher forms of monkeys and apes.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

The Pteropidae, or fruit-eating Bats, sometimes called flyingfoxes, are pretty evenly distributed over the tropical regions of the Old World and Australia. They range over all Africa and the whole of the Oriental Region, and northward, to Amoy in China and to the South of Japan. They are also found in the more fertile parts of Australia and Tasmania, and in the Pacific Islands as far east as the Marianne and Samoa Islands; but not in the Sandwich Islands or New Zealand.

The genera of bats are exceedingly numerous, but they are in a very unsettled state, and the synonymy is exceedingly confused. The details of their distribution cannot therefore be usefully entered into here. The Pteropidae differ so much from all other bats, that they are considered to form a distinct suborder of Chiroptera, and by some naturalists even a distinct order of Mammalia.

No fossil Pteropidae have been discovered.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

The Phyllostomidae, or simple leaf-nosed Bats, are confined to the Neotropical region, from Mexico and the Antilles to the southern limits of the forest region east of the Andes, and to about lat. 33° S. in Chili. None are found in the Nearctic region, with the exception of one species in California (Macrotus Californicus), closely allied to Mexican and West Indian forms. The celebrated blood-sucking vampyre bats of South America belong to this group. Two genera, Desmodus and Diphylla, form Dr. Peters' family Desmodidae. Mr. Dobson, in his recently published arrangement, divides the family into five groups — Mormopes, Vampyri, Glossophagae, Stenodermata, and Desmodontes. - Numerous remains of extinct species of this family have been found in the bone-caves of Brazil.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

The Rhinolophidae, or Horse-shoe Bats (so-called from a curiously-shaped membranous appendance to the nose), range over all the Ethiopian and Oriental regions, the Southern part of the Palaearctic region, Australia and Tasmania. They are most abundant and varied in the Oriental region, where twelve genera are found; while only five inhabit the Australian and Ethiopian regions respectively. Europe has only one genus and four species, mostly found in the southern parts, and none going further north than the latitude of England, where two species occur. Two others are found in Japan, at the opposite extremity of the Palaearctic region. *

The genera Nycteris and Megaderma, which range over the Ethiopian and Oriental regions to the Moluccas, are considered by Dr. Peters to form a distinct family, Megadermidae; and Mr. Dobson in his recent arrangement (published after our first Volume was printed) adopts the same family under the name of Nycteridae. The curious Indian genus Rhinopoma, which, following Dr. J. E. Gray, we have classed in this family, is considered by Mr. Dobson to belong to the Noctilionidae. .

Fossil Rhinolophidae.—Remains of a species of Rhinolophus still living in England, have been found in Kent's Cavern, near Torquay.

[blocks in formation]

1. a. s.a. 1.a.a. “ i.a. s.4 1.2.3.4 |1.a.s.. . I . 2. 3. 4.

The small bats constituting the family Vespertilionidae, have no nose-membrane, but an internal earlet or tragus, and often very large ears. They range over almost the whole globe, being apparently only limited by the necessity of procuring insect food. In America they are found as far north as Hudson's Bay and the Columbia river; and in Europe they approach, if they do not pass the Arctic circle. Such remote islands as the Azores, Bermudas, Fiji Islands, Sandwich Islands, and New Zealand, all possess species of this group of bats, some of which probably inhabit every island in warm or temperate parts of the globe. The genus Taphozous, which, in our Tables of Distribution in vol. i. we have included in this family, is placed by Mr. Dobson in his family Emballonuridae, which is equivalent to our next family, Noctilionidae. Fossil Vespertilionidae.—Several living European bats of this family—Scotophilus murinus, Plecotus auritus, Vespertilio noctula, and V. pipestrellus—have been found fossil in bone-caves in various parts of Europe. Extinct species of Vespertilio have occurred in the Lower Miocene at Mayence, in the Upper Miocene of the South of France, and in the Upper Eocene of the Paris basin. WOL. II.-13

« EelmineJätka »