DAKOTA AND NEBRASKA. 35 



less at its back part, and is longer in this position. The angle, though broken in the 

 specimen, appears to have been shorter and more robust. The lower part of the 

 masseteric fossa is more nearly parallel with the base of the jaw. 



The tubercular teeth contained in the specimen resemble those of the Wolf in 

 constitution, proportions, and mode of insertion. The first tubercular molar is rather 

 less in size than that of the Prairie Wolf, while the second is in a trifling degree 

 larger. 



A small fragment of the right side of the same jaw, represented in figure 3, plate 

 I, contains the sectorial or principal molar tooth. It has the same form and consti- 

 tution as in recent canine animals, is much smaller than in the Prairie Wolf, and 

 little exceeds that of the Red Fox, having about the same breadth, but being higher 

 and much more robust or thicker. 



Another fragment of the lower jaw, belonging to a different individual from any of 

 the preceding specimens, and represented in figure 4, plate I, also contains the 

 sectorial molar. The tooth is smaller than the one above described, and nearly 

 approaches in size that of the Red Fox, being about the same length, rather thicker, 

 but not quite so broad. The jaw fragment, containing the tooth, agrees nearly in 

 robustness with the corresponding portion of the larger jaw specimen above described. 



Measurements derived from the fossils referred to Amphicijoii vetus, in comparison 

 with those derived froni skulls of Ganis latrans and Ganis oecidentalis, are as follows : 



Amp. vetus. 

 Breadth of cranium immediately above the root of 



the zygoma and over the middle of the auditory 



meatus, . . , . .23 lines. 



Greatest breadth of cranium in the parietal region, 21 " 

 Narrowest portion of the cranium, . . 10 " 



Distance from the anterior margin of the occipital 



foramen to the anterior division of the sagittal 



crest, . . . . . . 34 " 30 " 37 



Length of sagittal crest, estimated in the fossil, .31 " 24 " 27 

 Long diameter of occipital condyles, or distance 



between the two ends, . . . 9 " 8J " 9 



Transverse diameter of occipital foramen, estimated 



in the fossil, . . . . . 8 " 7i " 8 



Distance between anterior margin of occipital fora- 

 men and the oval foramen, . . . 18 '• 19 J " 21 

 Breadth of glenoid cavity, . . . 12 " lOi " 12 

 Extent of glenoid cavity between the fore and back 



margins, . . . . . 6 " 5 " 6 



