ORYCTEROPODIDE 211 
not show the slightest tendency to an approximation towards the 
Old World forms, we are furnished with an additional reason for 
insisting on the radical distinctness of the latter, whose phylogeny 
must therefore for the present remain one of the many unsolved 
zoological problems.” 
The Aard-Varks (Earth-Pigs) as these creatures are commonly 
termed, from the name bestowed on them by the Dutch Boers of 
the Cape, are of nocturnal habits, sleeping during the day in their 
burrows, which are usually found in the neighbourhood of the tall 
hills or mounds made by termites. Indeed, wherever these hills are 
abundant it is stated there is a good chance of finding an Aard-Vark, 
the food of these animals consisting almost exclusively of termites 
and ants. 
Two existing species are recognised, namely the Cape Aard-Vark 
(0. afra) from South Africa, and another (0. ethiopicus) from the 
north-eastern parts of Africa, ranging into Egypt. An extinct 
species has been described from the Lower Pliocene of the Isle 
of Samos, in the Turkish Archipelago, differmg from the exist- 
ing forms by the larger proportionate size of the lateral meta- 
tarsals. 
Bibliography of Edentata.—No general work on the order has been published 
since that of Rapp (Anat. Untersuchungen iiber die Edentaten, 2d ed. 1852). 
Among numerous memoirs on special groups the following may be cited :— 
Myrmecophagide :—R. Owen, ‘‘ Anatomy of Great Anteater,” Trans. Zool. Soc. 
vol. iv.; G. Pouchet, MWém. sur le Grand Fourmilier, 1874; W. A. Forbes, 
‘‘Anat. of Great Anteater,” Proc. Zool. Soc. 1882, p. 287. Megatheriide :—R. 
Owen, Extinct Gigantic Sloth (Mylodon Robustus), 1842; Id., ‘‘On the Mega- 
therium,” Phil. Trans. 1851-56; J. Leidy, ‘‘Extinct Sloth-tribe of North 
America,” Smithsonian Contrib. to Knowledge, vii. 1855; H. Burmeister, 
Description de la République Argentine, t. iii. Mammiféres, 1879,—which contains 
full references to various memoirs by Owen, Gervais, Reinhardt, and others. 
Glyptodontide :—Owen, Catalogue of Fossil Mammals, Mus. Roy. Coll. Surgeons, 
1845 ; T. H. Huxley, ‘‘ Osteol. of Glyptodon,” Phil. Trans. 1865 ; H. Burmeister, 
Annales del Museo Publico de Buenos Aires, and Descript. de la République 
Argentine, 1879; H. Gervais and F. Ameghino, Les Mammiferes Fossiles de 
2 Amérique Méridionale, Paris, 1880,—which also contains a list of all the 
S. American Edentates described at that date. Dasypodide :—J. Murie, ‘‘Ana- 
tomy of Tolypeutes,” Trans. Linn. Soc. vol. xxx. 1874; A. H. Garrod, Proc. 
Zool. Soc. 1878. For Placentation of Edentates see W. Turner, Trans. Roy. Soc. 
Edin, xxvii. (1873) p. 72, and Journ. Anat. and Physiol. vols. viii. and x.; A. 
Milne-Edwards, Ann. Sciences Nat. [6] viii. p. 1; and for brain, P. Gervais, 
“«Formes cérébrales des Edentés,” Nowv. Arch. du Muséum, tom. v. ; W. Turner, 
Jour. Anatomy, i. 313 (1867). For the dentition of Orycteropus see O. Thomas, 
“A Milk Dentition in Orycteropus,” Proc. Roy. Soc. vol. xlvii. p. 246 (1890). 
Fuller observations on the mutual relations of the various families are given by 
W. H. Flower, “‘ On the Mutual Affinities of the Animals composing the Order 
Edentata,” Proc. Zool. Soc. 1882, p. 358. 
