AMBLYPODA. 



(Cope. Wheeler's Survey, vol. iv., pp. ijS ef ss.) 



" Mammalia, with small cerebral hemispheres which leave 

 the olfactory lobes and cerebellum exposed. The feet short 

 and plantigrade, with numerous (in the known genera, five) 

 digits, terminating in flat, hoof-bearing, ungual phalanges. 

 The seven bones of the carpus distinct, the unciform articu- 

 lating with both lunar and cuneiform. The astragalus flat, 

 without trochlear surface, and attached to the tibia with very 

 little freedom of movement ; its distal extremity divided into 

 two facets, one for the navicular, and the other more or less 

 for the cuboid. Molars inserted with enamel, with wide 

 crowns and transverse crests. A postglenoid process." 



This order falls naturally into two sub-orders : 



"I. A third trochanter on the femur, and a fossa for the 

 round ligament : no alisphenoid canal ; superior in- 

 cisors present Pantodonta. 



" II. No third trochanter, nor fossa for the round ligament ; 

 an alisphenoid canal ; no superior incisors. Dinocerata" 



This sub-order, Dinocerata, includes at present three dis- 

 tinct genera, Uintatherium, Leidv, Dinoceras, Marsh, and 

 Loxolophodon, Cope (also probably Megacerops, Leidy). These 

 three genera, in addition to the characters above given, are 

 marked by the possession of two or more osseous projections 

 from the upper surface of the head ; and of these the posterior 

 pair, developed from the parietals, are the largest. 



Synopsis of genera of 



