HOLLAND AND PETERSON: OSTEOLOGY OF THE CHALICOTHEROIDEA. 099 
of edentates by Cuvier, Kaup, Lartet, Gaudry, and Gervais, and were by them referred 
to independent genera. The ulna and radius, however, are much more like those of 
Diplacodon and Palwosyops than those of the Edentata. The humerus is remarkable 
by reason of the weak development of the deltoid crest, being thus differentiated from 
the Titanotheridz as well as from the Edentates. The entepicondylar foramen which 
is characteristic of most Edentates is wanting. The carpus in the proximal row has 
four and in the distal row three bones. The trapezium and metacarpal V are obsolete. 
A coéssification of two of the carpals, which is common in the Edentata, does not 
occur. Mc II is the shortest, nevertheless quite as thick as the two outer metacarpals 
of which Mc IV attains the greatest length; their distal articulating extremities are 
strongly convex and articulate with the first phalanges by a simple groove, which 
more particularly in the case of the outer digits lies almost entirely upon the superior 
surface of the bone. The distal articulating extremities of the first phalanges are, 
like the two which succeed them, deeply excavated in the middle, bipartite, and un- 
usually large, so that the digits were capable of being strongly bent backward even to 
the extent of partially covering the metacarpals. With this form of articulation, 
which strongly recalls that occurring in the Edentata, is united the deep fission of the 
terminal phalanges, much more like the claws of sloths than of ungulates, though re- 
sembling the cleft hoofs of the Typotheride and the Hyracoids among the Ungulata. 
The hind limbs are shorter than the fore limbs. The pelvis is unknown. The femur 
has an exceedingly weak third trochanter situated high up upon the shaft. The 
tibia and fibula are separate. The caleaneum is characterized by a very strong sus- 
tentaculum and broad articulating surfaces for the low astragalus, the distal truncated 
facets of which rest upon the navicular and in part upon the cuboid. The tibial 
trochlea of the astragalus is moderately arched and only feebly concave. The three 
metatarsals are noticeably shorter than the metacarpals; the phalanges are formed like 
those of the fore foot. 
The Chalicotheridze in their dentition and the structure of the skull show close 
affinity to the Titanotheres, but are strongly differentiated from them by the form 
of the highly mobile digits adapted to grasping, and by the deeply cleft, curved, and 
clawlike terminal phalanges. This structure of the feet induced Cuvier, Kaup, Lartet, 
Gaudry, and Gervais to attribute the foot bones, which they described under the 
generic names Macrotherium, Ancylotherium, Schizotherium, and Pernatheriwm, to the 
Edentata, assigning these genera a place near the genus Manis, in spite of the fact 
that the carpus and the tarsus have preserved the typical features of the corresponding 
portions of the Perissodactyla. Cope regards the Chalicotheride as forming a distinct 
order (Ancylopoda), but they most probably only represent a highly specialized offshoot 
of the Perissodactyla. Osborn regards them as descended from the Meniscotheride, 
with which both in dentition and skeletal structure they show numerous resemblances. 
