AND AVES OF NORTH AMERICA. 



77 



Width at anterior point of splenial, 

 " near extremity, 

 " an inch behind fork, 

 " between rami at same point, 



Teeth opposite symphysis, 



In. 



2. 



1.9 



1. 



13. 



Lin. 



4 

 13 



The larger teeth are all broken, bnl. one willi fang exposed, would probably measure when complete 1 in., 10 lin. 

 The. form of some of the smaller is well represented in Leidy's figures above cited; they are acuminate, strongly 

 incurved, of a full lenticular section, with an anterior and posterior raised cutting ridge, in the transverse plane of 

 the crown. The sides present numerous narrow weakly defined facets, and are in a, half protruded one, finely striate. 

 The alveoli do not open on the horizontal plane of the inside of the mandible, but the latter is raised above them 

 for the posterior half of the symphyseal portion of the jaw ; the Latter is more depressed towards the extremity. 

 Teeth from Other specimens and localities exhibit marked characters. They are all much curved and slender conic, 

 and subcylindrio ; the tip smooth, the remainder more or less extensively minutely .striata, but not fluted or ridged. 

 The fang is slightly flattened, in T. neooaesariensis the crowns-are relatively shorter, less curved and more obtuse; 



in both the anteroposterior dividing ridge is well marked. Part of the teeth attributed by Teidy to Hyposaurus 

 belong here ; see synonymes. 



The muzzle of a, larger individual from Birmingham, accompanied vertebra! of this species, with a smaller gavial 

 cranium in fragments ; and a cervical vertebra similar to that described under Bottosaurus harlani. Tts reference to 

 this species is not certain, but I give a figure of it. 



The lateral maxillo-premax illary suture is not preserved, so the number of premaxillary teeth cannot be exactly 

 ascertained; there are four to the line of the posterior margin el' the large incisive foramen, of which the anterior is 

 quite small. The, posterior palatal suture of the same element is prolonged in a narrow chevron on the median line 

 below, to opposite the eighth alveolus from the front; there are nine alveoli behind this point, to the broken 

 extremity. A noteworthy character consists in the presence at the. posterior part of the series of dee,]) fossae 

 between the maxillary alveola: for the reception of the mandibular teeth, showing that the latter did not project 

 externally between the former, as iii the existing gavial. The same struoture appears in the smaller cranium which 



accompanied It,* but, is not found in the Thor. neoeaesn.rieusis. 



Fig. 10. 



Fig. 20. 



• The fronto-parletal region of this one li described mi. In- head of H, brevtiplnla 

 AM Kill. PHILOBO. SOO. — VOL. XIV. 20 



