214 MEMOIRS OF THE CARNEGIE MUSEUM. 
Nacional de Buenos Aires, Tomo XV, p. 317 et seq., places his Homalotherium 
segovie in the Ancylopoda, and points out certain very remarkable features of the 
structure of the foot, which suggest that this form is related to the Chalicotheroidea. 
However the dentition and other features show that aside from the bifid condition 
of the unguals the animal had little in common with the Chalicotheres, a fact which 
has been well set forth by Gregory in his recent work to which reference has been 
made. Bifidity of the unguals is not confined to the Chalicotheroidea, as is well 
known to all students of comparative anatomy. It is a primitive structural 
feature, traces of which may be found in many widely separated families and 
genera. To point out these would necessitate the writing of a chapter, for which 
there is not space in the present memoir. 
Hyracotherium craspedotum Corr, Bull. U. S. Geol. Survey, VI, p. 198 (1881). 
Now referred to the Equide. | 
Hyracotherium venticolum Core, Bull. U. 8. Geol. Survey, VI, p. 198 (1881). Now 
referred to the Equide. 
Hyracothervum vortmani Corx, Bull. U. 8. Geol. Survey, VI, p. 198 (1881). This 
species was by Cope, l. c., p. 199, referred to Phenacodus, and is still regarded 
as belonging to the Phenacodontide. 
Lambdotherium popoagicum Corn, American Naturalist, Vol. XIV, p. 746 (1881), 
and L. brownianum Cops, l. c., p. 197, are both referred to the Titanotheres. 
Genus MrEnIscorHerium Cope, Report upon Vertebrate Fossils Discovered in 
New Mexico, p. 8 (Nov., 1874). 
In the paper here cited Professor Cope erected a new genus under the above 
name, the type being the species described by him under the name chamense. 
Professor H. F. Osborn in a paper published in the American Naturalist, February, 
1893, pp. 118-1383, in discussing the relationship of the various genera of the An- 
cylopoda calls attention to the fact that in Meniscotheriwm the same reduction in 
the anterior portion of the dental series and the same enlargement of the posterior 
portion, which is noticeable in the Ancylopoda, occurs, and also that the molars of 
Meniscotherium in both jaws have the same pattern as those of the Chalicotheres. 
He therefore suggests that Meniscotherium was perhaps in the line of the ancestry 
of the Ancylopoda. Subsequent studies which have resulted in the almost complete 
restoration of the skeleton of Meniscotherium, have demonstrated to the satis- 
faction of students that the resemblances in the dentition of Meniscotherium and 
the Chalicotheroidea, while pointing possibly to a remote common ancestry, do 
not suffice to establish the fact that Meniscotherium was ancestral to the Chali- 
