34 Bulletm American Museum of Natural History. [Vol. XIX, 



are median bones behind the glossohyal, baso-branchials (6. 

 br.). Certainly, the antero-posterior extent of this mass is 

 too great to belong to any one bone in the floor of the mouth. 



Along the right-hand border of Fig. 2 1 are seen the broken 

 edges of the dentary bone and of at least one, perhaps two 

 bones, between the latter and the tritoral surfaces described 

 above. Probably the hyoid and possibly a branchial arch 

 are thus represented. 



Fig. 22 presents, on the left-hand side, the right maxilla; on 

 the right, the tritoral surface of the parasphenoid. Between 

 them there is a toothed and pitted bone {pal.) which appears to 

 have been folded longitudinally through pressure. This bone 

 is taken to be the palatine. The parasphenoid, as seen, prob- 

 ably does not represent the whole width of this bone, but 

 posteriorly it was at least 1 2 mm. wide. The bones, both upper 

 and lower, of this triturating apparatus appear to be masses of 

 dense osseous tissue penetrated by deep pits. On the outer 

 border of the palatine are numerous sharp teeth. No teeth are 

 observable on the border of the maxilla, but doubtless the shal- 

 low pits there seen lodged small teeth, as in the type specimen. 



In both of the specimens described here there is present a 

 broad thin bone which lies on the snout occupying the region 

 between the anterior ends of the frontals and the premaxillse. 

 No median suture can be made out. Laterally the borders 

 extend outward as far as the outer ends of the premaxillae. 

 This bone appears to be separated from the premaxillae, but 

 the evidence is not satisfactory. The bodies of the premaxillae 

 are perfectly distinct from each other, but the bone referred 

 to may be their coossified ascending plates. In No. 21 11 the 

 bone extends backward about 15 mm. The large area occu- 

 pied by this bone and its scale-like appearance indicate that 

 it is not the ethmoid. 



This species differs from A. evoluUis in having a much nar- 

 rower band of teeth on the dentary. 



Anogmius aratus {Cope). 

 Plate II. 

 Anogmius aratus Cope (E. D.), Bull. U. S. Geol. and Geog. Surv. 

 Terrs. Ill, 1S77, p. 585. — Stewart (A.), Univ. Geol. Surv. Kan- 



