202 MEMOIRS OF THE CARNEGIE MUSEUM. 
To the Schizotheriinse may also be provisionally referred the new genus 
Eomoropus Osborn from the Eocene of North America, and Phyllotillon Pilgrim, 
from the Oligocene of India. There is no evidence in Homoropus of the retention 
of the pollex, but the fifth digit has not been nearly so much reduced as in Moropus. 
This genus probably represents a transition from the pentadactyl form in the 
direction of Moropus, which is functionally tridactyl. Phyllotillon is placed in this 
subfamily from purely stratigraphic considerations. 
Il. The Subfamily Moropodinew.—Professor O. C. Marsh with only a few 
fragments before him ventured, on what we now know to have been very in- 
sufficient grounds, to set up the family Moropodide, with the genus Moropus as 
the type. It was a shrewd guess, which somewhat overshot the mark. Never- 
theless, now that we have acquired a nearly complete knowledge of the osteology 
of the genus Moropus, it becomes very plain that we have good ground for separating 
it, and the somewhat closely allied Nestorithertwm (Ancylotherium, auct.) of Europe 
from the other genera of the family, for the following reasons: (1) in both these genera 
the astragalus does not touch the cuboid, a primitive feature; (2) the fifth digit 
persists in the manus of Moropus, though in Nestoritherium so far as material at 
present available seems to show, it has been lost; (3) both Moropus and Nestorithervum 
were characterized by having the fore and hind limbs more nearly subequal, than 
is the case in Macrotherium; (4) the articulating surface of the radius at its distal 
extremity is widened laterally and compressed in the antero-posterior direction in 
both genera, while in Macrotherium this surface is nearly quadrate. There are a 
number of other minor points of similarity between Moropus and Nestorithervum, 
which taken together show that they were more nearly related to each other than 
to the other genera of the family. 
Ill. The Subfamily Macrothertine.—Gervais recognized the family ‘‘ Macro- 
theride’’ (cf. Journal de Zodlogie, Vol. V, No. 6, p. 426). Following this as a 
precedent we have adopted the name here given for the third subfamily of the 
Chalicotheriide. To it we refer the genera Macrotherium, Chalicotherium, and 
Circotherium, gen. nov. These three genera are derived from later geological 
horizons than Schizotheritum, Macrotherium being derived from the Miocene of 
Sansan, France, Chalicotherium from the Pliocene of Eppelsheim, Germany, and 
Circotherium from the Upper Miocene or Pliocene of the Siwalik Hills in India. 
In Macrotherium we find no trace whatever of the first and fifth digits. ‘The manus 
of Chalicotherium is practically unknown, but its geological horizon is such as to 
seem to justify the belief that it probably did not retain these primitive features; 
in other respects, such as dentition, it is closely related to Macrotherium. The 
