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(C) Summary and Deductions as regards the
Order Chiroptera (continued).
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FAMILY IV. VESPERTILIONIDÆ. 27. Antrozous 28. Nyctophilus 29. Synotus. 30. Plecotus 31. Euderma 32. Otonycteris 33. Vesperugo 34. Chalinolobus 35. Scotophilus 36. Nycticejus . 37. Atalapha 38. Harpiocephalus 39. Vespertilio 40. Kerivoula . 41. Natalus . 42. Thyroptera 43. Myxopoda. 44. Miniopterus
FAMILY V. EMBALLONURIDÆ. 45. Furia 46. Amorphochilus 47. Emballonura . 48. Colëura.. 49. Rhynchonycteris 50. Saccopteryx 51. Cormura 52. Taphozous. 53. Diclidurus. 54. Noctilio 55. Rhinopoma 56. Cheiromeles 57. Molossus. 58. Nyctinomus 59. Mystacops
(c) Summary and Deductions as regards the
Order Chiroptera (continued).
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FAMILY VI. PHYLLOSTOMIDÆ. 60. Chilonycteris . 61. Mormops 62. Lonchorhina 63. Macrotus 64. Macrophyllum 65. Vampyrus 66. Lophostoma 67. Schizostoma 68. Glyphonycteris 69. Trachyops. 70. Phylloderma 71. Phyllostoma 72. Tylostoma 73. Mi 74. Carollia. 75. Rhinophylla 76. Glossophaga 77. Phyllonycteris 78. Monophyllus . 79. Ischnoglossa 80. Lonchoglossa 81. Glossonycteris 82. Charonycteris 83. Lichonycteris. 84. Artibeus 85. Vampyrops 86. Chiroderma 87. Sternoderma 88. Ectophylla. 89. Ametrida 90. Pygoderma 91. Sturnira 92. Brachyphylla. 93. Centurio 94, Desmodus 95. Diphylla
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1. The Order of Chiroptera, or Bats, contains about 530 known species which are divided into ninety-five genera and six families.
2. They are found in every part of the world except within the Arctic and Antarctic Circles, and even in many islands where no other mammals occur.
3. The Fruit-bats (Pteropodidae) are met with only in the Old World, and mainly within the tropics.
4. The Vampires (Phyllostomatidæ) are entirely restricted to the Neotropical Region, except two or three species (out of eighty) which have passed over the boundaries into the Nearctic Region.
5. Two forms of the Vampires (Desmodus and Diphylla), having their dentition and digestive organs specially modified for that purpose, feed on the blood of living animals.
SECTION IV.-DISTRIBUTION OF RODENTS
Rodents are by far the most numerous of all the Orders of Mammals, comprising, according to a moderate calculation, nearly 1400 species which are arranged in 159 genera belonging to twenty-one distinct families. They are also among the most universally distributed of terrestrial mammals, being found in all latitudes high and low, and abundant in every part of the earth except Australia, where they are feebly represented by a few genera and species. The Rodents, especially the Mice (Muridx), to which family rather more than half their number belong, are still imperfectly known; their arrangement and classi
fication have recently undergone important changes, and continual discoveries of new species and new alliances are made by several busy naturalists who are engaged mainly on a study of the smaller mammals. Under these circumstances it is hardly necessary for our present purpose to mention more than the names of most of the twenty-one families which constitute this complicated group, but we shall endeavour to pick out, as we go through them, some of the most noticeable facts connected with the distribution of these mammals.
Adopting Mr. Thomas's recent classification of the genera of this group 1 (with a few slight deviations) as the best authority, we find the Anomaluridæ, a singular group of Flying-Squirrel-like Rodents, at the head of the Order. This family, with its three genera (Anomalurus, Idiurus, and Zenkerella), is purely Ethiopian, the eleven or twelve species which are referred to it occurring only in tropical Africa. Passing on to the next family, the Squirrels (Sciuridæ), we have an extensive group of about 240 species divided into eleven genera distributed nearly all over the earth's surface, with the exception of the Australian Region and Madagascar, where they are entirely deficient. The most numerous genus is that of the true Squirrels (Sciurus) which, subject to the exception just mentioned, is fairly distributed over the whole of the earth.
The Castoride, or Beavers, which come next, are represented in the present day only by the genus Castor, , with two species, one of which occurs in the high latitudes of the Palæarctic and the other in those of the Nearctic Region. These two species are closely allied and perhaps scarcely distinguishable.
1“On the genera of Rodents,” P. 2. S. 1896, p. 1012. Cf. Palmer, “Science," N. S., vi., p. 103 (1897).
The Haplodontiidæ, or Sewellels, allied to the Squirrels, contain only the single genus Haplodontia, the species of which are confined to the Nearctic Region.
In the fourth family of the Rodents we meet with more familiar objects. The Gliridæ, or Dormice, with six genera and about nineteen or twenty species, have a curious distribution, being found only in the Ethiopian, Oriental, and Palæarctic Regions. Each of these Regions, however, has its peculiar genera, true Glis and its allies belonging to the Palæarctic Region, whilst Graphiurus is strictly Ethiopian, and the two remaining genera are restricted to the Oriental Region.
We now come to the Mice, or Muridæ, which, as already indicated, are exceedingly numerous and all-pervading creatures. Mr. Thomas places the 730 species of this family in seventy-eight genera. Mice are most numerous, perhaps, in the tropics, but are also well represented in Arctic latitudes, and in the shape of Lemmings (Lemmus), extend far towards the Pole.
They are not abundant in Australia proper, being represented there chiefly by the peculiar genus Hydromys and a few species of Mus. In Madagascar the seven genera of Muridæ met with are likewise altogether restricted to that anomalous island.
The Mole- rats (Spalacidæ), which follow next in Mr. Thomas's series, are a small and peculiar group, the members of which imitate the subterranean life of the Moles. The typical genus Spalax, with eight species, is confined to the Palæarctic Region, whilst the Bamboo Rats (Rhizomys), represent the group in