86 Bulletin American Museum of Natural History. [Vol. XIX, 



intervening between the epiotic and pterotic processes. There 

 appear to be good reasons for drawing as we have, the lateral 

 boundaries of the frontals ; but the suture between the squa- 

 mosal, 5g., and the postorbital, pt. or., cannot be determined. 

 The frontals extend far forward, so that they occupy by far 

 the greatest portion of the upper surface of the skull. In 

 the median line in front is the ethmoid, eik. The exact 

 limits of this have not been determined. Posteriorly it ex- 

 pands and it appears to divide, sending a branch, nah, back- 

 ward close to the mesial border of each premaxilla ; but it is 

 more probable that these lateral branches are distinct bones, 

 the nasals. The premaxilla, pmx., is a thin, elongated, 

 sculptured bone, having small teeth along the lower border, 



except in front. It is ap- 



plied closely to the palatine. 

 Its teeth appear to have 

 been directed forward. This 

 is shown in Figure 70, pmx., 

 and the same appearance is 

 presented by so many speci- 

 mens that this position of 

 the teeth appears to be the 



Fig. 70. E7npo nepaholica Cope. No. 1776. 

 X \. Part of skull, lateral view, art.^ articular ; 

 den., dentary ; ec.pt., ectopterygoid ; en. ft., en- 

 topterygoid ; fM., ethmoid ; y>-., frontal ; m.pt.. 



metapterygoid ; »iJi., maxilla ; nil .'", nasal? : Jia., ■• 



parietal ; pmsc., premaxilla ; //. 0., postorbital ; nOrmai OUC. 



smx., supramaxilla. r^\^ •^^ i-v /- 



Ihe maxilla, rigs. 69, 70, 

 mx., is a long, compressed, toothless bone which forms the 

 posterior border of the mouth. Its anterior end overlaps for 

 a long distance the premaxilla, its extremity in both the speci- 

 mens figured here rising above the upper border of the pre- 

 maxilla. The same position is shown in the skull figured by 

 Loomis. Figure 71, No. 1969, shows the skull seen from 

 below. The parasphenoid is very broad in front. It has 

 possessed no teeth. The articular surface for the hyomandi- 

 bular is short. The vomer does not appear in this specimen. 

 It is the bone which Cope called and figured with doubt 

 a pharyngeal. Stewart calls it the ethmoid. It is possibly 

 consolidated with the ethmoid, but certainly both bones 

 are represented. It possesses a varying number, one to four, 

 of rows of teeth. Various specimens indicate that other 



