PETERSON: A REVISION OF THE ENTELODONTID A: stil 
of sufficient importance to warrant, when the many other differences are also taken 
into account, the generic separation of the two forms. From the very complete 
description of Archwotheriwm ingens by Professor Scott it is quite plain that the Oligo- 
cene genus was already capable of high speed, which appears to have been a require- 
ment of these animals throughout the successive geological ages in which they 
existed. We naturally look for a reduction in the length of the humerus and femur 
accompanied by the retention or increase of the length of the lower portions of the 
limbs among the later survivors of the family. The limbs of Dinohyus which fortu- 
nately were found with the skeleton, show a greater advance than is found in Archzo- 
therium ingens in those characters which are necessary for speed and endurance. 
z 
Fic. 67. External View of Right Scapula of Type of D. hollandi Peterson. } nat. size. 
©The philosophy of the increase in length of the lower part of the limb in recent hoofed mammals has been dis- 
cussed by Dr. Matthew in the Memoirs of the American Museum of Natural History, Vol. I, Part 7, p. 432 (1901). 
