CORYPHODON 209 



canine tooth only, and was brought up from a depth of 160 feet 

 during; the makino; of a well at Camberwell. More abundant 

 remains have since been found in North America. 



This genus had a large head, and in some specimens traces of 

 the " horn cores," so marked in the related Dinoceras, are to be 

 noticed. The skull is l;)road behind and narrowed in front ; the 

 roofing bones show the cellular spaces so characteristic of the 

 Elephant. The jugal bone, however, is not, as it is in the 

 Elephant, placed in the middle of the somewhat massive zygomatic 

 arch. As in some other primitive Ungulates (e.g. Phenacodus) 

 there are twenty dorso-lumbar vertebrae, of which fifteen bore ribs. 



The scapula seems to have possessed a peculiar leaf-like form, 

 swelling in the middle and ending almost in a point above. It 

 has a well-marked spine, and the acromion projects much. The 

 fore- as well as the hind-feet are in a state of transition between 

 plantigradism and digitigradism. It was at one time held that 

 the animal was digitigrade as to the fore-feet and plantigrade as to 

 the hind-feet. Though, as has been pointed out, it is a fact that 

 the hind-feet are often on a different plane of evolution from the 

 fore-feet, it seems that this amount of difference does not characterise 

 any Ungulate, not excepting the genus now under consideration. 



The toes are very spreading. The pelvic girdle is of great 

 strength and broadness. The femur, as in the Perissodactyles, 

 has a well -developed third trochanter; but whereas in this 

 particidar the hind-limli is Perissodactyle, it is Artiodactyle in 

 the fact that the tiljia and the fibula articulate with the astragalus 

 and calcaneum. The ridged teeth have given the name to the genus. 



A curious featm^e in the structure of the genus are the 

 slender spines of the dorsal vertebrae, which contrast with the 

 enormous ones of some other Ungulates — more curious in this 

 genus, which is of heavy build, than in the lighter Pantolamtda. 

 The back of the animal is short, and the limbs are very spreading, 

 so that the gait was doubtless shuffling. The large head, and 

 short and heavy limbs and limb girdles added probably to its 

 cumbrous walk or trot. The canines are great tusks, and spread 

 out on both sides of the mouth. ^ 



The late Professor Cope, in 1874, described the probable appear- 

 ance of the Coryphodon in the following words : — " The general 

 appearance of the Coryphodons, as determined by the skeleton 



^ Osborn, Bull. Amer. ihis. Nat. Hist. x. 1398, p. 81. 

 VOL. X P 



