136 Annals of the Carnegie Museum. 



The Cranium. 



In our collection there is one nearly complete skull, without the 

 lower jaw (No. 96) of a very old individual, in which the structure 

 of the molar and premolar teeth, except in M.-^, has been obliterated 

 by wear. A second skull (No. 98), also wanting the lower jaw, but 

 probably pertaining to a younger, though fully adult animal, shows 

 the molars and premolars on either side in splendid condition, save 

 P.i, which has been lost. A third specimen, (No. 97), consists of a 

 complete lower jaw with all the teeth in position on either side, with 

 the exception of I.-g, which is represented only by an alveolus. No. 

 96 is the cranium of a very old individual, apparently a female. When 

 found in the matrix it lay on one side, and had been subjected to great 

 pressure, resulting in considerable distortion, the entire cranium being 

 compressed laterally. It is proportionately long and narrow, exhibit- 

 ing few rugosities. There is a distinct, rather sharp, and somewhat 

 elevated sagittal crest, expanding posteriorly into the slightly elevated, 

 narrow, emarginate occipital crest, which overhangs the occipital con- 

 dyles. The paroccipital process is short and blunt, curves forward 

 inferiorly, but does not come in contact with the longer, but rather 

 slender, postglenoid process, so that the meatus auditorius externus 

 is left open below. The zygomata are of considerable vertical 

 diameter, but are exceptionally thin in transverse diameter. The 

 squamosals enter into the construction of the zygomata to a greater 

 extent than do the malars. The orbit is nearly circular in outline 

 with a decided postorbital constriction due to the presence of pro- 

 nounced postorbital processes both on the frontals and malars. The 

 brain-case is small. There is a marked temporal constriction. The 

 infraorbital foramen is placed directly above the middle of P. A. 

 The nasal incision is very deep ; its posterior margin is on a line 

 drawn vertically from the posterior border of FA. The premaxillaries 

 are long and slender and have an extensive contact with the maxillaries. 

 The maxillopremaxillary suture extends from in front of the canine 

 to a point directly above the middle of P.i. The premaxillaries do 

 not come in contact with the nasals and do not coossify at their an- 

 terior extremities. The nasals are long, slender and acute. They 

 terminate anteriorly almost directly above the anterior border of the 

 premaxillaries. A side view of the skull, one fourth natural size, is 

 shown in Plate II, Fig. i. 



