190 NATURAL HISTORY. 



great passage for the spinal cord, and the two processes on the frontal bone, add to the curious 

 appearance of this " bumpy " skull. The pelvis is remarkable in its structure, and is open in front. 



Some of these animals have the bands of the armour not attached, as has been mentioned, 

 to the muscles of the back and to the head, but have them adherent to the skin of the back to the 

 edge ; and the sides and under part of the body are then covered with woolly hair. These are the 

 largest animals of the two, and are found in Bolivia. The others are from Mendoza and Chili 

 These curious animals live, partly, mole-like lives. 



From what may be gleaned by reading the previous pages about the Edentates, it will appear that 

 the order is a very remarkable one, and that it is interesting on account of the different external 

 appearance of the species, their diverse modes of life, and singularly restricted localities. Evidently, 

 there has been much degeneration in some of the anatomical characters of many of the species, and 

 especially in those whose foot bones and neck vertebrae have joined more or less. The singular 

 resemblance which some species present, in various points of their anatomy, to the lower animals, is 

 very interesting, as is also their wonderful relation, in points of structure, with a number of extinct 

 Edentata, most of which were gigantic. 



The Edentata, called also Bruta by Linnaeus, form an order, the characters of which are, that there 

 are teeth of one or two kinds all very similar, and often wanting. The incisors are not developed 

 except in one group, and the rest have either molars which are separate, and numerous and simple, 

 or there are none. The extremities are clawed, and the tongue is more or less elongated. The great 

 groups of this order are the Tardigrada, or slow movers, which have a short face, long limbs, and 

 small tail, and the body is covered with crisp hair; and the Effodientia, or diggers, which have long 

 faces and worm-like tongues, with short limbs. 



The Sloths form the only family of the Tardigrada, and the Effodientia are divided into the 

 genera Manis, the scaly Ant-eaters ; Dasypus, the Armadillos ; Cldamydophorus, the Pichiciagos ; Oryc- 

 terop'tcs, the Ant-Bears ; and Myrmecophaya, the American Ant-eaters. The Sloths form three genera 

 Cholcepus, Bradypus, and Arctojnthecus. Amongst the Ant-eaters, the genus Manis may stand alone. 

 The genus Dasypus may be divided, for the sake of convenience, into the subdivisions Priodontes, 

 Kabassous, Euphractes, Cachicames, and Tolypeutes. The other genera need no subdivision. 



The fossil Edentata are mostly gigantic, and formerly lived in Europe and in the Americas. 

 The European kinds would, were they now living, belong probably to the group of Pangolins, and 

 they are placed in the extinct genera Pervatherium, Macrotkerium, and Ancylotherium. In the 

 Pliocene deposits of North America, there are large Edentates belonging to the genus Morotherium, 

 and the previous Miocene deposits contain Moropus. The later, or Post- Pliocene strata of North and 

 South America, contain species of Mylodon and Megalonyx, Megatherium, Scelidotherium, Ccelodon, 

 and Sphenodon ; they constitute a group of Terrestrial Sloths the Gravigrada. In Cuba, the fossil 

 huge Gravigrade Sloths are of the genera Megalocnus and Myomorphus. The Armadillo group are 

 found fossil in South America, and the genera are Chlamydotherium, Euryodon, Heterodon, Pachy- 

 therium, and Schistopleuron. The modern genera are found with these, and the gigantic Armadillo- 

 like animal, the Glyptodon, lived contemporaneously with the others, and possessed many strange 

 peculiarities in its skeleton. The Ant-eaters are represented by a fossil form called Glossotherium. 

 The oldest Edentates of the American Continent are found in North America, unless there is a 

 Miocene group of them in South America, which is by no means an improbable supposition. The 

 European Ant-eaters now found fossil lived in the Eocene, Miocene, and Pliocene ages. 



With regard to the discovery of recent and closely-allied species of Manis, in South Africa and Hin- 

 dostan, it may be said that they are relics of the old forms of the intermediate and now sunken land, 

 between Eastern Africa and India, which existed before the last upheaval of the Himalayas. The evident 

 structural affinity between the Effodient Edentata of South America and Africa, although the genera 

 are different, adds to the interest of the corresponding, and in some instances greater, resemblance of 

 many African and South American fresh-water fish and plants. The geologist looks back in the 

 remote ages of the globe, when the great land sxirfaces and seas of the world were rather across the 

 earth than in their present longitudinal position, in order to explain this remarkable similarity. 



P. MARTIN DUNCAN. 



