CEOCODILIA. 163 



of this species are less rugose than those of the C. davis, especially in the 

 plane in front of the interorbital ledge. It is there absolutely smooth. 

 Posterior to the bridge, the fossas ai'e frequently no wider than their inter- 

 spaces, which is not the case in C. davis. The middle line of the posterior 

 half of the muzzle is nearly smooth. The sculpture of the malar bones is 

 very strong, and that of the superior middle of the maxillaries nearly as 

 much so; that of the lower jaw is distinct. 



The form of the skull is Avedge-shaped, and it is flat above, without 

 keels or crests. The "interorbital ledge" is an abrupt change of level, 

 with an outline concave forwards. It is somewhat like the corresponding 

 locality in the existing jacares of South America. The extremity of the 

 premaxillary drops off abruptly from the nares. The outline of the upper 

 jaw is sinuous; the orbits are vertical in direction. The posterior part of 

 th« squamosal bone is narrow, with nearlj? vertical interno-posterior side, 

 and acuminate extremity. The posterior edge of the quadrate condyle is 

 emarginate. The angular process is rather narrow, and is obtusely rounded 

 at the extremity. The lateral mandibular foramen extends as far forwards 

 as the line of the middle of the orbit. The symphysis of the lower jaw is 

 of medium length, reaching the seventh tooth from the front. The chin is 

 wedge-shaped. 



The teeth of the upper jaw are : premaxillary, 5 ; maxillary, 4, the canine, 

 and 11. The anterior teeth are elongate conic, with somewhat compressed 

 crowns, and weak fore-and-aft cutting-edges ; the posterior ones have very 

 short ci'owns. The enamel is finely and roughly striate. In the mandible 

 the first tooth is larger than the two succeeding; the fourth is the very 

 large canine; those following the canine have about half its diameter. In 

 this part of the dentition the C. affinis is like the C. davis. 



The sutures are well preserved in one of the crania. The posterior 

 part of the parietal is nearly as wide as that of the frontal. The anterior 

 part of the latter is much produced between the prefrontals. The nasals 

 extend backwards behind the apices of the prefrontals and lachrymals, and 

 are continued forwards as an acute process into the external nostrils to the 

 third of their long diameter, as in C. davis. 



