52 MAURICE G. MEHL 



tooth. The pit does not perforate the facial surface of the bone, 

 however, as is occasionally the case in the alligators. 



The lower jaws are represented by an almost perfect right 

 ramus and a goodly portion of the left, including the symphyseal 

 and articular regions. The sculpturing of the mandible is much the 

 same as in any of the alligators; the dentary is marked by small, 

 deep pits and more or less prominent longitudinal grooves. In 

 the region back of and below the external mandibular foramen the 

 surface is dotted with deep rounded pits, irregular in size but dis- 

 tinct. In the relation of the various mandibular elements there is 

 nothing of particular interest except perhaps in the unusual for- 

 ward extent of the splenial. This element extends far forward 

 and takes an ample part in the symphysis. Each ramus bears 

 nineteen teeth, very similar, in general, to the maxillary teeth. 

 The fourth tooth is the largest in the series, round in section, and 

 measures fully 6 mm. in diameter at the base. The crown is 

 largely missing, but was apparently sharply conical, and the indi- 

 cations are that there was a faint anterior and posterior carina 

 extending down the sides. This was probably the condition of the 

 anterior four teeth in each ramus. The root of the first tooth 

 indicates that it was somewhat larger (about 4 mm. in diameter) 

 than the two subequal teeth that follow. 



Immediately following the fourth tooth is a series of seven, all 

 comparatively short and slender and averaging about 2 mm. in 

 diameter at the base and 4.5 mm. in height. These small teeth 

 have slightly swollen crowns and a faint suggestion of anterior and 

 posterior carina. The posterior eight teeth are subequal in size 

 and quite like the eleventh maxillary tooth described above. 



The nature of the bite is alligatoroid in that the teeth of the 

 mandible all close within the teeth of the upper jaw and the fourth 

 mandibular tooth fits into a deep socket in the palate surface. 



THE VERTEBRAL COLUMN 



Eight of the cervical vertebrae are present, all but the atlas. 

 With the exception of the axis, they are all very pronounced pro- 

 coelous. Although the union between the centrum and the arch 

 is clearly distinguishable, the two parts are as a rule closely united. 



