262 



ABPEXDIX. 



3 — 3; canm3s, 1—1, 1 — 1 ; premolars, 4 — 4,4 — 4; molars, 3 — 3, 

 3 — 3 = 44 ; that is 44 fauctionally developed teeth. The molars 

 are of the simple four-lobed pattern, resembling in this respect 

 the suilline Artiodactyla or hotrs and peccaries ; in fact on this 

 aiccount it is a matter of some surprise that the animal should 



molars, reduced canines and a more elongated foot. An approach to ibis 

 condition, as far at least as the molars are concerned, is found in a new 

 form recently described by Prof. Cope under the name Manteodon (pro- 

 pliecy tooth). The Arnblyimla, says Prof. Cope in his Report on Capt. 

 Wheeler's Survey (W. lOOih Mer., Pt. ii, Vol. IV, p. 233), are as yet con- 

 fined to the Eocene peiiod exclusively, and are found both in Europe and 

 this country. In points of affinity to the hoofed orders generally they 

 occupy an interesting and important position, being in all probability the 

 oldest and affording the most generalized condition known among the 

 ungulates. The brain capacity is exceedingly small in proportion to the 

 size of the other parts of the skeleton, and from casts made from the brain 



case itself we are warranted 

 in assigning these animals 

 a position among the low- 

 est mammalia; they are 

 lower in brain development 

 even than any of the Mar- 

 sripials. The feet are very 

 short, are provided with 

 five fully developed toes, 

 and have their entire plan- 

 tar and palmar surfaces ap- 

 plied to the ground, as in 

 the modern bears. The as- 

 tragalus is greatly flattened 

 from above downward, and 

 is primitive and character- 

 istic. It displays on irs in- 

 ferior surface flattened ar- 

 ticular facets for both na- 

 vicul.ir and cuboid bones 

 which share the articula- 

 tion about ccjually. Onthe 

 superior part, the surface 

 articulating with the tibia 

 is almost flat, a condition 

 ■which must have lendered 

 the ankle joint capable of 

 very little movement, and 

 giving to these animals a peculiarly awkward and shambling gait. It is 

 not dTfficull to perceive that these small-brained, five-toed, and plantigrade 

 Amblypoda could easily have furnished a starting point for both the Artio- 

 dacUjla and PerUsodactyla, and, as we have good reasons to believe, did 

 give origin to the Proboscidea or elephants. 



iglU hind-foot of 



species ofCorvpliodon (Amblvpod). 

 n-iturul .ize (Cop.-). 



