356 Dr. Riley and Mr. S. Stutchbury on Saurian 



much wider than in any of the family of the Lizards, and it approaches more nearly to the monitors 

 and crocodiles than to any other recent genus. 



Tibia.— V\2iie XXX., fig-. 6, reduced to one half. 



This bone we conceive to be a tibia^ but its outlines and extremities 

 are so much dilapidated, that we are not able to make out a further deter- 

 mination. 



Fibula.— Phte XXX., fig. 7, 7 a. natural size. 



This figure represents a left fibula detached from the matrix; the superior 

 half only remains, but it is in a perfect state. 



7 a. Is a section of the superior edge. 



The bone more nearly resembles the fibula of a Crocodile than any other. 



Metacarpal or Metatarsal Bones and Uncial Phalanges. — Plate XXX., fig-. 

 8 to 13, natural size. 



These bones belong to the extremities, but whether to anterior or posterior 

 we do not attempt to decide. It is probable, from the elongated character of 

 fig-. 9, that it is a metatarsal or metacarpal bone. Fig. 8 is evidently one 

 of the phalanges, probably a penultimate ; its great difference in trans- 

 verse diameter shows that it could not have belonged to the same member as 

 fig. 9. 



Figs. 10 to 13 are evidently uncial phalanges, and present all the characters 

 of those of a Saurian. Fig. 10 measures 2 in. -Vths along its convex edge, 

 its articular extremity is hollow, and has a process projecting considerably 

 backwards, on its upper and lower edges. This form of its articular cavity 

 would evidently prevent extension as well as flexion to any great extent. 



Conclusion. — The considerations which arise from the study of these re- 

 mains are various and important; and we have a further proof of the truth of 

 the opinion, that the more ancient the strata, the more the animal remains 

 differ from existing types. 



In the specimen of the lower jaw, we have an animal with teeth contained 

 in alveoli, a character separating these remains from all recent Lizards, and, 

 connecting them with those Saurians having alveoli, as the Crocodiles, another 

 of the many instances of extinct types intermediate to the existing ones, the 

 antiquity of these remains being greater than that of any other vertebrated 

 animals excepting Fishes ; the sutures connecting the annular portion of 



