334 A MEMOIR UPON THE GENUS 
preniolar The part of the ])alate preserved in this specimen shows this region to 
have been more elongated and narrow than in P. fialudosus ■, the palate was also 
strongly arched as in the sknll of Tclmatotherium. A specimen of tins species m 
the Princeton collection containing the malar insertion is interesting, as it shows the 
close relationship in form of this bone to that of relmatothenum. As in the latter 
-enus, the malar arises very abruptly from the cheek and diverges widely from it. 
Its superior face below the orbit is convex ; its inferior surface is divided by a sharp 
lono-itudinal ridge. A small orbital process of the malar is present in this specimen, 
and” posterior to this region, the malar is very thin and strongly compressed. The 
orbital floor, like that of Telrnatother'ium, is much elongated. Dr. Leidy, in Ins 
description of the facial specimen already referred to, says “ the space behind the 
anterior abutment of the zygoma indicates a temporal fossa of large capacity ” ; and 
again “the orbit is low and is directed obliquel^^ foreward and downward. In 
advance of the prominent anterior orbital margin the side of the tace is nearly 
vertical. The infraorbital foramen is rather large, and is situated over the jKisitioii 
of the last premolar. ” 
Mandible . — The form of the jaw in P. minor closely resembles that of 
P. paludosus. The horizontal ramus is rather short, thick and deep below the last 
molar. The posterior border of the jaiv is sinuous in outline, but this margin is not 
so strongly inflected as in the larger species. The ascending ramus is short and 
deep, its horizontal diameter on a line with the last molar is abln’cviated in contra- 
distinction to the elongation of this region in the jaw of P. longirostris, wdiere the 
ascending ramus is Avidely prolonged posteriorly. The condyle is short and heavy ; 
it is horizontal in position and separated by a shallow notch from the long and 
slender coronoid process. The masseteric fossa is broad ami shallow, and is not 
separated bj- a ridge from the horizontal portion of the jaw. The angular ])ortion 
is thin and everted. The jaw symphysis, is very short and not 2 )rocunibent. 
There is a single mental foramen situated beloAv premolar 3. 
AePENDrcrL.AK Skeletox. 
Scapula, No. 10,277 A. — A lower portion of a smaller scapula than that of P. 
paludosus shoidd probably be referred to P. minor. The specimen is vein" much 
damaged, so that is impossible to give all its characters. The general form of the 
scapula in this species closely .resembles that of P. paludosus. The glenoid is 
deeply concave. The coracoid is very much broken, but its position and form is 
the same as in the larger species. The anterior border of the scapula aboA’e the 
coracoid is concave, and then rises suddenly to the strongly convex superior portion. 
There is a prominent tuberosity upon the posterior border, but it is much more 
reduced than in P. paludosus. The origin of the spine is nearer the glenoid border 
than in the larger species. The internal surface of the scapula is flat Avith a coiiA'ex 
posterior portion. The dimensions of this sjjecimen and its characters correspond 
very closely to one in the Academy of Natural Sciences of Philadelphia, Avhich 
probably belongs to P. inino7'. 
