PLATE II. 



Enchodus petrosus Cope. 



Figure 1. — hoc, basioccipital; eoc, exoccipital; c, diagram of occipital 

 condyle, trisected by sutures, the upper two-thirds being the exoccipitals, 

 and the lower third the basioccipital; ojn, opisthotic; op, opercular; pa, 

 parasphenoid; pal, left palatine; pal, ventral view; paid, dorsal view of 

 same (a mesial view of this palatine is shown in plate III, fig. 1) ; pro, 

 prootic; pr, pterotic; sp, sphenotic. X %. No. 804. 



Fig. 2. — Portion of right dentaiy figured in plate III, figure 9, show- 

 ing the contour, /-/, or the alveolar border in a vertical plane passing 

 througn the middle of the scars of the discarded teeth, a is the fora- 

 men of the blood vessel supplying the fang. The broken lines at the 

 base of the fang indicate the position of the former bases of fangs, in a 

 median section through this portion of the dentary, n being the base of 

 the last discarded fang, and o that of the next to the last. 6, c, d and e 

 are the bases of the posterior teeth. There is to be seen one scar in 

 front of 6, two between b and c, and three between d and e. d leans 

 cephalad over the scar at its base, and this scar appears to be crowded 

 forward. The dotted portion in the lower part of the figure is plaster 

 of Paris, x Yi. No. 803. 



Figs. 3, 4, and 5. — An opercular, supraclavicle, and portions of a 

 dentary and ai-tieular of a species much larger than any other in the 

 collection. X %. No. 805. 



