Mar., 1904.] 



KNO\VI.i:iH}E & SCIENTIFIC NEWS. 



27 



cameloid characters had already made their appearance. 

 On the other hand, the skull (lie;. 21 was short and 

 rabbit-like, showing none of the characteristic features of 

 those df the modern canu'ls. 



Reaching the period of the Lower Miocene, we come 

 to a genus, Gomphothtrium, in which there is a consider- 

 able increase in the matter of bodily size, the two meta- 

 podial bones (or those which unite in the later forms to 

 constitute the cannon-bone) being fully double the length 

 of the corresponding elements in Pivtylopus. Moreover, 

 these bones, although still separate, ha\e their adjacent 

 surfaces much more closely applied than is tiie case in 

 the latter, .\gain, in tiiis and the earlier genera the 

 terminal toe-bones indicate that the foot was of the 

 normal hoofed type. On the other hand, in the skull 

 (fig. 2) the socket of the ej'e is completely surrounded by 

 bone: while the dentition begins to appro.vimate to the 

 camel type — notably bj- the circumstance that the lower 

 canine is either separated by a gap from the outermost 

 incisor, or that its crown assumes a backwardly curved 

 shape. Brief mention must suffice for I'roiolalris of the 

 Middle Miocene, in which, while no cannon-bone is 

 formed, the first and second pairs of incisor teeth are 

 retained, and the limbs and feet are short and dispro- 

 portionately small. 



In the Upper Miocene, on the other hand, we come to 

 a very distinct type — Procamchis — which is clearly entitled 

 to be regarded as a camel, and approximates in size to 

 a small llama. Here the metapodials have at least 

 partially united to form a cannon-bone : the skull has 

 assumed the elongated form characteristic of modern 

 camels, with the loss of the first and second pairs of 



rig. 3. — The Bones of the Mind-Foot of Poebrotherjum, showinf; the 

 distinct metatarsars. uhich coalesce in the higher forms into the 

 cannon -bone. 



upper incisors, and the development of gaps in front of 

 and behind each of the next three teeth, that is to say, 

 the third incisor, the canine, and the first cheek-tooth. 

 The approximately contemporaneous Plianclienia makes 

 another step by the loss of the second lower cheek-tooth. 

 Both these genera have the toe-bones of the irregular 

 nodular form distinctive of the modern camels, so that 



we may safely infer thai ihe fici themselves had assumed 

 the cushion type. 



In one species of Pi'ocininiiis llic iiict.ipoilial hones 

 coalesced into a cannon-bone late in life; but when we 

 come to the Pleistocene Caiiiclops such union took place 

 at an early stage of existence, and was thoroughly com- 

 plete. In the living members of the group it occurs 



Fig. 4. Hind Cannon-bone of a modern Llama to contrast with the 

 foot of ' ' f'oebrotheriiim,'* and to show the type characteristic 

 of " Procamelas" and hlg:her forms. 



even before birth. The species of Camelops were pro- 

 bably fully as large as llamas (including guanaco and 

 vicuna), and some of them, at any rate, resembled these 

 animals as regards the number of teeth, the incisors 

 being reduced to one upper and three lower pairs, and 

 the cheek-teeth to four or fi\-e in the upper and four in 

 the lower jaw ; the total number of teeth thus being 

 28 or 30 in place of the 44 of Poehi-otlieii'mn. Tiie sole 

 difference between Camelops and Llama seems to consist 

 in certain structural details of the lower cheek-teeth. 

 An allied extinct genus (Kschatiui) is also distinguished 

 by certain features in the dentition. 



All the foregoing genera are exclusively North 

 ,\merican. \ lower jaw from the F'leistocene deposits of 

 that Continent has, however, been referred to the true 

 camels (Camelas), w^hich differ from the llamas, among 

 other features, by their greater bodily size, well developed 

 hump, or humps, the presence of five pairs of lower 

 cheek-teeth, and the complete bony ring round the socket 

 of the eye. 



Outside America, remains of true camels are met with 

 in the Lower Pliocene Siwalik strata of India, as well 

 as in the Pleistocene of Soutli-Eastern Lurope and 

 Algeria ; and it is noteworthy that the cheek-teeth of the 

 Siwalik camel {Camelus sivalensis) display a structural 

 feature now exhibited by those of the llamas. Prom 

 Pleistocene or Pliocene in China have been obtained 

 remains of a large camel-like animal named Paracamelus, 

 which also shows certain signs of afiiiiity with the llamas 

 in respect of its cheek-teeth. 



The above survey, brief as it is, suffices to show that 

 the huge camels of the present day have been gradually 

 e\olved from creatures not bigger than a hare, on lines 

 closely paralleled in the case of the horse. In one 



