OF LIVING ELEPHANTS. 185 



than in any quadruped, and the occipital foramen is directed back- 

 wards, as in ordinary cases. This cavity is as broad from right to left, 

 as it is long, a proportion of which we have no instance except in the 

 cetacea. 



There is no osseous tentorium ; the middle fossae are of considerable 

 depth ; still the separating ridges of bone are not at all acute. The sella 

 turcica is well marked, but the clinoid processes are very little so; the 

 cribriform plate is tolerably large, of moderate depth, and has a thin 

 and prominent crista galli. 



2. — Of the Lower Jaw. 

 The lower jaw of the elephant is as distinctive for this genus, as any 

 other of its parts. 



See it in profile, pi. 7, fig. 1 ; pi. 8, fig. 2 and 3; and pi. 18, fig. 2 

 and 3; as seen from above, pi. 11, fig. 2 and 3. 



Its two rami form together anteriorly an angle of more than sixty 

 desfrees. They are extremely thick, convex on the sides, rounded at 

 their lower edge, and unite anteriorly in a semi-cylindrical canal ter- 

 minated by a pointed beak. 



Viewed in profile they are very high vertically, and terminate ante- 

 riorly each by a line (o h, pi. 8, jig. 2,) which descends obliquely 

 forwards to the beak, and forms the edges of the canal just now men- 

 tioned. 



The ascending ramus is nearly as high as the dental ramus is long. 

 There is no well marked posterior angle ; but the form posteriorly 

 (c d e, same Jig.) is a portion of a circle, and the posterior edge is full 

 and rounded. 



The coronoid process /"is rounded, less elevated than the condyloid 



g, from which it is separated by an arch of but little depth, ascending 



obliquely backwards. Its anterior edge is inclined forwards, and sharp. 



The condyloid process g has its articular surface nearly in the form 



of a segment of a sphere. (See pi. 1 1 , Jig-. 2 and 3.) 



The foramen for the maxillary nerve is very large and situate very 

 high under the condyle, near the posterior edge of the ascending 

 ramus, and at its internal surface ; the mental foramina {h,fig. 2,pl.S), 

 two in number, are small, and pierced on the outside near the anterior 

 canal. 



3. — Of the Bones of the Trunk^. 

 The spine of the elephant consists of seven cervical vertebrse, twenty 

 dorsal, three lumbar, four sacral, and twenty-four or twenty-five coccy- 

 geal vertebrae. 



This animal has only five true ribs, and fifteen false. 

 Its ribs are in general known by being less curved and thinner 

 downwards than those of any other large aninial. Their entire sternal 

 half has its two edges sharp, and is almost straight. The vertebral 

 third only is perceptibly arched, almost cj^lindrical, and hollowed by 

 a semicanal at the anterior edge. Their tubercles have but little 

 prominence. The two first on each side are nearly straight, and con- 

 siderably widened towards the sternum. 



The rhinoceros has its ribs more arched, and thicker ; this is true, 



* That part of the body consisting of the back bone, ribs, &c. 



