12 
anterior. In 7. roulini, this plate does not so much exceed the sacral 
plate. (2) The pubes and ilia are not so horizontal, but meet at nearly a 
right angle, and (3) the ischiopubic common suture is considerably longer. 
(4) The obturator foramen is a more elongate oval. 
The femur is very similar to that of 7. roulini, being no smaller in 
relative size. (1) The great trochanter is wider fure and aft, and with 
margin more continued on the anterior aspect of the extremity of the 
shaft. (2) The great trochanter is nearer the middle of the length. 
(3) The condyle surfaces are continuous with the rotular, not isolated as 
in 7. roulini. The latter also (4) lacks the two fossz on the outer mar- 
gin of the external seen in H. ewimius. (5) The rotular groove is also 
narrower in the latter and not so deeply excavated as in 7. roulint. 
The tibéa is (1) reduced in size, and especially contracted distally ; the 
relative widths of the ends are 6 cm: 3.5; in 7. rouliné 7.5 cm to 5 
(2) The crest is more prominent and is deeply fissured by a groove, which 
is represented by a shallow concavity in 7. rowlini. The groove (8) ex- 
ternal to this is deeper. (4) The posterior inner tuberosity of the distal 
end, is more median, hence, the inner trochlear groove is further removed 
from the anterior inner malleolus, which has, therefore, a greater inner 
)not outer) extent. 
The tarsus (1) is generally longer and narrower, except in the case of 
the cuboid bone (2) which is shorter than in 7. roulini. (8) The astra- 
galus has a narrower neck which therefore appears more on the inner 
side. (4) The facet for the cuboid is smaller. (5) The inner tuberosity | 
of the head ismore prominent. (6) The calcaneum is more slender, with 
larger cuboid facet, especially posteriorly. The metatarsus is absolutely 
nearly as long as in 7. roulini, and therefore relatively longer and more 
slender. (2) The median (III) is nearly similar to the others in width; 
in the 7. rowlini, much larger than the lateral. 
The phalanges of the first cross series are more contracted distally. 
The more important differences between the skeletons of the two species 
in addition to those pointed out under the head of the genus, are those 
of the ulna, the scapula, the lumbar vertebre, the ilium and the crest of 
the tibia. The scapula is more like that of Tapirus terrestris, while the 
ilium is approximated by that of 7. malayanus among living species ; 
its form leans towards the Equine series, and not to the Paleotherotd. 
Conclusion. From the preceding it is evident that there lived in North 
America during thé Eocene period, a type of Yapiride only differing 
generically from that now existing in South America. Thus one form of 
the many peculiar and primitive ones of that time still persists in the 
Tropics and Southern hemisphere, which claims more ancient character 
than the Rhinocerus, Elephants, and other remains of Miocene time. 
The affinities of Cercoleptes and Nasua to the types of the same period 
have been already indicated,* and with the present case may be regarded 
as confirmatory of the proposition stating the early geologic state of the 
existing Fauna Neotropica. 
* See on the Primitive types of the Mammalian Orders, 1873. See Origin of Genera, p. 99 and 
preced, 
