CEOCODILIA. 159 



rests on the quadrate, is broadly truncate, instead of acuminate, and its 

 postero-interior surface is subhorizontal, instead of vertical. Thirdly, the 

 basal part of the angular process of the mandible is expanded inwards into 

 a shelf with convex border. One or the other, particularly the first and 

 second, of these characters have been verified on several individuals of the 

 C. affinis. 



The general form of the cranium is much like that of the wider forms 

 of the Crocodilus americanus. The front and top of muzzle are flat, and 

 thei'e ai-e no crests or ridges on either. The maxillary border is strongly 

 convex to the position of the posterior canine tooth, and is deeply notched 

 to accommodate the inferior canine. The muzzle is shortened in fi-ont of 

 the nares, since the premaxillary border descends steeply from their ante- 

 rior margin. In consequence of the mature age of the individual, the 

 sutures of the skull are obliterated. The united nasal bones project into 

 the nareal opening for about one-third the long diameter. The orbits are 

 somewhat narrowed by the convexity of the internal border of the malar 

 bones. The interorbital space is plane, of course, excepting the sculpture, 

 but there is a slight tendency to a transverse ridge about opposite the mid- 

 dle of the orbits. The superior border of the quadrate condyle is deeply 

 notched near the middle, to receive a corresponding angle of the mandible. 

 The projecting angular process is very wide at the base, its superior surface 

 having two concavities, of which the inner is nearly twice as wide as the 

 external. The inner convex border contracts rapidly distally, leaving the 

 obtuse free end a little wider than long, and directed inwards. 



The sculpture is roughly honeycombed on the superior surfaces, 

 especially on the squamosal, post-frontal, frontal, and top of muzzle. On the 

 middle line, posterior to the middle of the latter, the sculpture is reduced to 

 a few longitudinal grooves, closely placed. The pits are much smaller on 

 the borders of the maxillary and front of the maxillary. The rami of the 

 mandible have longitudinal grooves on the external sides, and the anterior 

 part of the chin has small pits. 



The symphysis of the mandible is like that of C. affinis, somewhat 

 elongate for this genus, and produced and rather narrowed to the apex. 

 The rami separate opposite the second tooth behind the notch of the upper 



