234 FAUNA ANTIQUA SIYALENSIS. 



advanced, as to prevent tlie posterior cylinder of the tooth, in 

 the lower jaw from undergoing any change, the front and fore- 

 most cylinder only of this penultimate tooth having undergone 

 this singular alteration and arrived at this diseased form. 



In referrmg to the table of measurements above given, the 

 excess in size of the fossil is the most prominent feature, but 

 the relative dimensions of the diJSerent parts, with one excep- 

 tion, bear a close affinity to those of the existing Camel. In 

 the jaw of the latter there appears to be a greater dej^th at 

 the alveolus of the ultimate molar at the com m encement of 

 the ascending branch, which may possibly result in some degree 

 from age and the more perfect development of the teeth ; but 

 in other respects the resemblance is striking. The excej)tion 

 to which we refer is in the second measurement, showing the 

 breadth between the rami, or ascending branches to the rear, 

 a difference of some importance, as it involves in the structure 

 of the cranial portion of the skull an increase of width, and a 

 greater distance between the articulating or glenoid surfaces 

 for the condyles of the lower jaw. We are borne out in the 

 correctness of this inference, by the remains of our second 

 species of Camel, which fortunately is very perfect in the 

 cranium, and where the breadth and form of this region in 

 comparison with that of the existing Camel are very different. 

 To this, however, we shall refer in its proper place, satisfying 

 oiu'selves with the conclusion that the Camelus Sivalensis and 

 the Camelus antiquus corresponded in this respect, and that the 

 former differed from the existing Camel in the form and excess 

 of width of the cranium. In comparing the teeth of the fossil 

 represented in Plate XVIII. figs. 3, 4, and 5, with those of the 

 Camelus dromedarius we observe no difference, excepting that 

 which may have arisen from their difference in age. That of the 

 fossil must have been considerable, as may be observed in the 

 wear and flattened surface of the fourth or pointed incisor. 

 The intermediate incisive teeth have been slightly disarranged 

 in the matrix ; and it will be observed in the drawing that 

 one of these teeth has been displaced, and is now situated 

 above, embedded in the rock. The grinding surfaces of all 

 the incisors are much worn, and all marks of the lateral nick 

 completely obliterated. On the opposite side to that repre- 

 sented in the plate, the canine tooth of the upper jaw is 

 situated in position with its point downwards, embedded in 

 the mass of matrix, which, it may be observed, reposes on 

 the anterior parts of the fossil. This canine is much worn 

 both on the point and on the anterior side ; and its resem- 

 blance to that of the Camel of the present day is sufficiently 

 close to make any further comparison unnecessary. 



Figs. 6 and 6 a (PI. LXXXVII. F.A.S.) are portions of the 



