TOXOCHELYIDJE. 



175 



quadrate. On the right side the whole ot the quadratojugal is missing, but on the left most of 

 it is present, but crusht. The interorbital space is 22 mm. wide. The orbit has an antero- 

 posterior length of 38 mm. The nasal opening is 15 mm. wide. 



The pterygoid portion of the palate (fig. 222), where narrowest, is 20 mm. wide, being 

 narrower than in T ' . latiremis. The distance between the ends of the pterygoid processes is 

 46 mm.; whereas, in T '. latiremis of the same size, the distance is 53 mm. The postpalatine 

 foramina have a diameter of 5 mm.; those of T. latiremis, a diameter of 13 mm. 



FIGS. 221 AND 222. Toxochelys elkader. Skull of type. 



221. Upper view. 



222. Lower view. 



The choans are slightly further from the snout than in T. latiremis, the anterior boundary 

 being 28 mm. away. This region is constructed much as in T . procax, but the choanae are 

 relatively nearer the snout. The triturating surface of the upper jaw is 21 mm. wide, including 

 a roughened ridge 5 mm. wide on the palatine. 



The lower jaw (fig. 223) is apparently somewhat crusht downward. It is complete, except 

 that both articulars appear to be missing. The triturating surface looks directly upward, is 

 slightly concave transversely, and its inner border overhangs the inner face of the bone. The 



surface is 15 mm. wide at the middle of the length, widening 

 forward, becoming narrower backward. The symphysis has 

 a width of 23 mm., both above and below. 



So far as is to be seen, the plastral bones do not differ 

 from those of T. serrifer. One coracoid is observed. The 

 length is 85 mm.; the width of the free end, 48 mm. The bone 

 is therefore both shorter jand wider [than that of T. latiremis. 

 Some of the ways in which this species differs from 

 T. latiremis have been mentioned; but the lower jaws are 

 especially different. In T. latiremis the grinding-surface is 

 narrower and it slopes downward and inward toward the inner 

 face. 



T. serrifer differs in having the grinding-surface more con- 

 cave from front to back, of equal width from end to end, and 

 the superior line of the symphysis equal to the width of the 

 grinding-surface, and to the lower line of the symphysis. 



In T. stenopora the triturating surface of the lower jaw 

 slopes downward and inward to meet the inner face of the jaw. The upper line of the sym- 

 physis slopes downward and backward and is somewhat shorter than the lower line. The 

 nasal opening is contracted. The length of the prefrontal suture is equal only to one-half 



FIG. 223. Toxochelys elkader. 

 Lower jaw of type, with section 

 at symphysis. Xj. 



