120 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 51. 



ture is shown in one of Keinhardt's figures. This ridge appears to 

 be on the vomer. 



In our specimen the greater part of the palate, the front of the 

 vomer, and the ethmoid bones have been broken away. A part of 

 the hard palate is seen in front, and the underside of this is rough. 

 In the rear of this injured region the cribriform plate has been 

 broken through so as to leave a small opening to the brain-cavity 

 on the left side and a much larger one on the right. In front of 

 this, on the right side (left side of the illustration, pi. T, fig. 2), 

 are seen openings into sinuses in the frontal bone. The larger of 

 these on each side extend backward to the hinder end of the frontal. 

 Some of the plates of bone nearer the midline evidently belong to 

 the olfactory apparatus. On the right side there remains about 

 30 mm. of the malar bone. On the left side the front part of the 

 malar is missing, but the hinder part is present. The malar was a 

 triradiate bone. The anterior process joined the lachrymal. The 

 hinder process was directed upward and backward and had a notch 

 in the hinder part of the lower border to receive the anterior end of 

 the zygomatic process of the temporal bone. The lower process is 

 pointed, and it descended about 60 mm. below the level of the palate. 



The maxilla on the right side contains the four teeth which are 

 characteristic of this genus (pi. 6; pi. 7, fig. 2). The length of 

 the tooth row is 57 mm. Between each of the teeth and its neighbors 

 is a space of about 5 mm. The grinding surfaces of the teeth stand 

 below the hard palate hardly more than 5 mm. They must have 

 been about on a level with it Avhen the bone was covered with flesh. 



The following measurements are obtained from the teeth. The 

 length of the tooth is taken at the middle of its width and far enough 

 above the grinding surface to avoid the effects of wear. 



Measurements of teeth in millimeters. 



As usual in the genus, there is for each tooth a front and a rear 

 cutting edge. These are separated by a wide furrow. In the second 

 and the third teeth this furrow turns backward, to end at the inner 

 hinder angle of the tooth. The first, second, and third teeth have a 

 somewhat greater fore-and-aft diameter at the inner side than that 

 given in the table ; while the last tooth measures 9.5 mm. on the outer 

 face. The front face of the first tooth is flat transversely, that of 



