GENERAL REMARKS. 



687 



were well developed in both male and female. There was 

 no diastema (interdental space) between the canines and 

 premolars, which differed from the molars by being smaller 

 and simpler in form. The molars had very short crowns, 

 each of which had six cusps (prominences). The skull 

 and brain were small, and the head was carried nearly 

 in a line with the neck. 



Phenacodus, whose remains have been found in America 

 and in Switzerland, somewhat resembled a wolf in appear- 

 ance, and was about twenty-one inches high. He walked 





Fig. 642. — Hyracotheriiim (J actual height). 



chiefly on his 2nd, 3rd, and 4th toes, which were provided 

 with small hoofs ; the 3rd toe being wider and longer 

 than the others. He was active, had a long tail, power- 

 ful hind quarters, was probably omnivorous and in- 

 habited swampy ground and low-lying forests. His 

 enemies were probably Creodonts, which in Eocene times 

 represented our carnivora (flesh eaters). The following 

 forms are believed to connect this extremely primitive 

 ungulate with the recent Equidee. 



Hyracotherium (Eohippus, Fig. 642), was found 

 by Professor Marsh in the Lower Eocene of New 

 Mexico, and several species have been described, 



