1884. ] The Condylarthra. 905 
The M. tapiacitis Cope, is the least species, and presents some 
dental peculiarities (Fig. 26, 4). 
With this genus and family we close the Condylarthra. That 
the order gave origin to the Amblypoda is highly probable. Be- 
sides this order, the Proboscidea and Hyracoidea must be traced 
back to it. It stands as the remote ancestors of the Perissodac- 
tyla and Artiodactyla, through the Amblypoda. They are the 
primitive hoofed mammals or Ungulata, and probably existed, 
like the Plagiaulacidze, in Cretaceous time. 
* The discovery of the Condylartha is a good illustration of 
what may be derived from persevering scientific research. Prior 
to this event the history and affinities of the great division of the 
oofed Mammalia were, for its earlier stages, a total blank. Few 
but specialized forms were known, and the affiliations of these 
with the two aberrant groups of Proboscidea and Hyracoidea, 
and with each other, could not be guessed. Now the phylogeny 
is, in the main, certain, and the point of connection with the 
clawed (unguiculate) orders, not difficult to discern. 
