PAL.EOSYOPS LEIDY, AND ITS AJJJEB. 
370 
no post-preniolar 1 diastema in the jaw of D. elaius. I have plaotMl the type jaw 
of T. hyognathus in the genus Telmatotheriiim because its inferior premolar 4 
appears to still retain the simpler character found in all the Palccosyopina. The 
following table of measurements will illustrate the variation in the length of the 
symphyses above described. 
Measurements to Illustrate the Increase in Length of Jaw Symitiv.sis. 
P. paludosus 
No. 10,009. 
T. variety 
No. 10,184. 
T. cultridens 
No. 10,3(31. 
Tfhnatothcriuui 
No. 10,274. 
hyognathus 
No. 10,273. 
M. 
M. 
M. 
M. 
M. 
Length of symphysis 
•092 
•108 
•115 
•11.5 
•130 
Breadth behind premolar 1 
.065 
■043 
•050 
•055 
■OdO 
Length of post-canine diast. 
•000 
•on 
•017 
022 
■an 
Length of post-premolar 1 diast . 
■015 
•018 
■015 
■Oil 
•017 
The Axial Skeleton . — I have already described the peculiarities of the a.xial 
skeleton of Palceosyops palndosus. In many respects it resembles that of the Tapir, 
although in the specialization of the articular processes of the posterior a.xial region 
it differs widely from the latter. It was found that the atlas and axis closely' 
resemble those of the Tapir, the former being pierced by two foramina for the first 
cervical nerve. The transverse process of the atlas is perforated by a large inter- 
vertebral canal. The vertebra) of the anterior dorsal region are very lu*avy with 
strong neural spines; on the posterior part of the dorsal region the vertebral zyga- 
pophy'ses become nearly as involute in form as in some of the Artiodaetyles [. Itililo- 
capra). In this character the vertebra' of Palceosyops dei)art widely' from all recent 
Perissodactydes except Equus which has the zygapophyses of the posterior dorsal 
and lumbar regions involute in form. 
Appendicular Skeleton . — The general form of the scapula is, as far as known, 
constant throughout this subfamily. In P. paludosus it was rather broader and 
heavier than in L. laticeps Avhere the spine of the scapida was (piite obli<pu* in |)osi- 
tion. The pn’imitive character of the scapula in this subfamily as compared with that 
of recent Perissodactyles is indicated in the ivant of a corac(Kscai)ular notch, by the 
presence of a large tuberosity for muscular insertion and, most important, the large 
development of the coracoid process. The form of the scapula of Pahrosyops is 
found to be rather intermediate between that of Tapirus and Rhinoceros, 'fhe 
trochlem of the humerus, in form and subdivision, are rather different from thos«* 
of the Tapir, the internal trochlea being large and more obliipie in i>osit ion, whereas 
the external part of the external trochlea is bevelled off instead of In-ing concave as 
in the Tapir. This is Also the case in the smaller species of the genus. In P.pa/u- 
fl'cjzwthe internal trochlea is very large and broad, while the external has a tendency 
to become rounded, and does not show its subdivisions as ])lainly as in the larger 
species. This character is more strongly marked in the Rhinoceros when* the 
external trochlea has no bevelled portion, this face being vertical. 
50 JOUR. A. N. S. PHILA., VOL. IX. 
