Tertiary Vertebrata of the West. 471 



produced into a curved hook. The neck is longer than in the 

 Dinocerata. 



The genus Manteodon has two interior cusps to the last upper 

 molar tooth, and all the upper molars have a marked V shape. 

 Ectacodon has only one inner cusp, and one external cusp to the 

 last upper molar, while only the two anterior molars have the 

 posterior V form. Coryplwdon has no external cusp ; and the 

 astragalus is transverse, with an internal hook. This genus is 

 thought to have resembled the Bears in aspect more than any living 

 animals, except that their feet were more like those of the Elephants. 

 The feet indicate a heavy elephantine type of movement, owing to 

 the inflexibility of the ankle. The species varied in size between 

 the bulk of a Tapir and that of an Ox ; they were omnivorous, though 

 armed with tusks in both jaws, which are fully as marked as those of 

 Carnivora. There are about twelve American species, some of which 

 are well known from New Mexico. They are distinguished chiefly 

 by relative length of the premaxillary bones, and variations in 

 development and form of the cusps and tubercles of the teeth. 



The material for an account of this genus is less full than in 

 Professor Cope's report in Lieut. Wheeler's survey. The species 

 C. elephantopus most nearly approaches the genus Manteodon, and is 

 defined by the inner half of the posterior crest of the hinder upper 

 molar, forming a V shape, like that of the penultimate molar. The 

 profile of the skull is Tapiroid ; the frontal and parietal bones are 

 wide above, so as to overhang the temporal fossae. The jaw is con- 

 tracted behind the canine teeth, and the expansion of the pre- 

 maxillary region is rounded. The zygomatic arch widens, so that 

 the malar bone is carried out laterally far beyond the plane of the 

 maxillary bone. All traces of sutures are obliterated, and the pos- 

 terior half of the head is roughened above by shallow pits and 

 wrinkles like those seen in many Eeptiles. The palatal surface 

 is widest between the posterior incisors. The interspaces between 

 the incisor teeth are as wide as their roots. The large canine teeth 

 are well worn on the anterior face, and the molars are well worn by 

 mastication. Bathmodon is an allied genus, in which the astragalus 

 is subquadrate, narrower, and wants the internal hook seen in 

 Coryphodon. At present the skull is unknown, and it is possible 

 that some species of Coryphodon may belong to this type. 



Bathmodon pachypus is the only Coryphodont with the pelvis well 

 preserved. The wide peduncles of the ilia resemble those of the 

 Elephant ; and if the crest of the ilium of the Camel were more 

 convex, it would resemble Bathmodon. The peduncle is stouter than 

 in the Horse, Tapir, or Pig. The limb bones appear to be more 

 robust than in species of Coryphodon. Metalophodon differs from 

 Coryphodon in the structure of its molar teeth, though the dental 

 formula is the same. All the premolars have the single external V 

 pattern ; the first upper molar only has two external Vs, of which 

 the anterior is represented by a subconical cusp, while the posterior 

 V is large. The genus is known from two species. 



The next suborder, Dinocerata, is especially distinguished from the 



