322 CLASS xv. 



in face and jaws. Nostrils subterminal, with posterior apertures of 

 air-passages distinct. Single row of small teeth in upper jaw, with 

 two or three larger tusks at the anterior extremity, and a continua- 

 tion of small teeth external and anterior to the tusks. Palatine 

 (vomerine) teeth in a transverse row, and a longitudinal row on 

 each side of the outer margin. Single row of teeth in lower jaw 

 with a large tusk on each side of the symphysis. 



The teeth are slender in proportion to their length, not very acute, 

 striated towards the base ; for their structure see OWEN Odontogr. pp. 202 

 205, PL 64 A, figs. 2, 3, 64 B, fig. i, fig. 2. They are anchylosed in 

 shallow sockets, as in certain fishes. New Red sandstone of Warwick and 

 Leamington, and lower part of the Triassic series (Keuper) in Germany. 

 OWEN renders it probable that the foot-prints referred to the so-named 

 Cheirotherium were made by Labyrinthodon. Brit. Assoc. Iteport, 1841, 

 p. 1 88. Some of the species attained a length of several feet. 



Archegosaurus GOLDFUSS. Teeth similar in structure to those of 

 Labyrinthodon, but the foldings less complex. Body covered with 

 small scales. 



Sp. Archegosaurus Dechenii; cranium six and a half inches long, breadth half 

 the length; and other species; GOLDFUSS Beitrdge zur Fauna der Stein- 

 kohlengebirges, Bonn, 1847, 4to. 



Parabatrachus OWEN. Sp. Parabatrachus Colei; from the Coal Shale, 

 Glasgow; OWEN Journ. of Geol. Soc. ix. 1853, pp. 66 70. 



Brachyops OWEN. 



Brachyops laticeps; sandstone of the lower Jurassic period; Journ. Geol. 

 Soc. i. 1845, pp. 318 322. 



Telerpeton MANTELL. 



Sp. Telerpeton elginense: this is perhaps the most ancient reptile known. 

 The fragments were discovered in the Devonian rocks of Morayshire; 

 Quarterly Journ. Geol. Soc. 1852, vin. p. 100. It is referred to the sala- 

 manders, but with lacertine characters. 



Serpentes. 

 Palceophis OWEN. Allied to Python and Boa. 



Sp. Palceophis toliapicus. London clay at Sheppey (Eocene tertiary). Brifl 

 Assoc. 1841, p. 1 80, &c. 



For other genera see OWEN Palceontogr. Soc. 1850, pp. 5768. 



Enaliosauria OWEN. 



Nostrils near the summit of head. Vertebrae biconcave or nearly 

 flat. Ilium not connected to sacral ribs by synchondrosis, bul 





