136 



MAURICE G. MEHL 



gradually, attaining finally a width of 84 mm. The anterior 

 extremity is bent abruptly downward and reaches a distance of 

 39 mm. below the plane of the ventral surface. 



THE PALATE 



Within the line of the alveoli on the ventral surface is a promi- 

 nent rounded ridge on either side, as is noted in Palaeorhinus bran- 

 sini Williston^ and Mystriosuchus. It crowds close along the alveoli 

 throughout the entire length of the premaxillae and gradually flattens 



Fig. 4. — Angistorhinns gracilis, lateral view showing apparent arrangement of 

 bones about the narial region, one-third natural size. 



out on the maxillae. The teeth have all dropped from the alveoli 

 except in the down-curved portion of the rostrum. Here four large 

 ones are to be seen broken off close up to the premaxillae, two on 

 each side. They are all round in section and measure about 15 mm. 

 in diameter. If one may judge from a similar specimen in which 

 these terminal teeth are preserved, they reached a length of from 

 80 mm. to 90 mm. or more in this form. In the premaxillae there 

 are 23 alveoli on each side. These, with the exception of the two 

 anterior ones described above, are approximately of one size, aver- 



' J. H. Lees, "The Skull of Palaeorhinus," Jour. Geo!., XV (1907), 124. 



