Tertiary Vertebrata of the West. 469 



spheres are unusually small, being only one-fourth longer than the 

 cerebellum, from which they are separated by a thick tentorium. In 

 the same way, deep grooves divide the hemispheres from each other, 

 and from the olfactory lobes in front. Nine species are recognized, 

 seven of which are denned by the characters of teeth in the mandible. 

 In the description of P. Vortmani indications are given that the 

 spine of the scapula is recurved, as in the Amblypoda and Proboscidea; 

 while the bone differs chiefly from that of the Dinocerata and 

 Proboscidea in the addition of an acromion, which gives a resem- 

 blance to some Rodents like the Squirrel. The tuberosities of the 

 humerus are less developed than in most Diplarthra. The propor- 

 tions of the ulna and radius are similar to those of Hyrax, but the 

 distal articulation of the ulna is like that of a Carnivore. The 

 pelvis is intermediate between that of Hyrax on the one hand and 

 Canis and TJrsus on the other. The femur is rather more robust than 

 that of the Tapir. The astragalus is small, and resembles that of 

 Hyrachyns. This species was about as large as a Bulldog, but with 

 a smaller head and shorter neck, which had more the proportions of 

 a Raccoon. The feet resembled those of the Tapir or Rhinoceros, 

 but with a pair of short toes on each side which did not reach the 

 ground. The tail was like that of a Dog. 



The third family of Condylarthra, Meniscotheriida?, includes the 

 single genus Meniscotherium. The animal was about as large as a 

 Pox, less slender than Phenacodus, with a short muzzle and large 

 eyes, the robust proportions of a Raccoon, and a large tail. It was 

 one-third larger than the Cape Hyrax, probably a vegetable feeder. 

 and distinguished by its dentition. The upper molars have inter- 

 mediate tubercles, of which the anterior are crescent-shaped, the 

 posterior oblique. The inferior molars and last premolar have two 

 V-shaped folds. The brain cavity is relatively larger than in Phena- 

 codus. Three species of the genus are known. The comparisons 

 chiefly indicate relations with Phenacodus and Hyracotherium. 



The Amblypoda next claim attention. This group comprises 

 mammals with small cerebral hemispheres, which leave the olfactory 

 lobes and cerebellum exposed. The species have short plantigrade 

 feet, terminating in the known genera in five digits, which have 

 flat hoof-bearing terminal phalanges. The seven bones of the carpus 

 are distinct. The molar teeth have wide crowns and crests invested 

 with enamel. The structure of the feet indicates an affinity to the 

 Proboscidea, which is most obvious in the hind foot, the principal 

 difference being that, while the navicular bone extends over the 

 distal end of the astragalus in Proboscidea, the navicular bone is so 

 short in Amblypoda as to allow the cuboid to come in contact with 

 the astragalus. The nearest approach to this condition of the 

 Amblypoda is seen in the Miocene Perissodactylate genus Srjmborodon, 

 where the cuboid and navicular facets are flat, and separated by an 

 oblique line, so as to be similarly incapable of hinge-like movements. 

 In the fore foot the difference between Amblypoda and Proboscidea 

 consists in the alternating position of the elements of the two carpal 

 rows. This alternating condition is usual in the cold-blooded 



