10 FOSSIL REPTILES OF DORSET. 



bed of calcareous mud, obtained through the energy of Mr. J. H. 

 Beckles, and associated with the dwarf crocodiles Nannosuchus and 

 Theriosuchus, which are described below. 



FAMILY TELEOSAURUS, Geoff. 



This extinct family has the centra of the vertebras concave at both 

 ends, jaws long and narrow, teeth slender. Cuvier grouped it with 

 the living Crocodiles, but Geoffrey St. Hilaire, observing a difference 

 in the position of the posterior nares, gave it the generic name of 

 Teleosaurus, and subsequently added another genus, Steneosaurus. 

 The number has since been increased to seven," including Metrio- 

 rhynchus. All were probably marine and sublittoral, differing in 

 their mode of respiration from the fluviatile Crocodiles, and 

 Gavials. 



GENUS STENEOSARUS, Geoff. 

 STENEOSAURUS MANSELII, Hulke. 



This species is determined by my distinguished friend, J. W. 

 Hulke, Esq., F.R.S., whose name will often appear in the course of 

 this paper, especially in connection with the Kimmeridge Reptiles. 

 The back portion of its skull, the left temporal arcade, and the 

 entire snout show it to have had a long triangular-shaped head, 

 converging almost in a straight line from the base of the skull to 

 the snout. The external nostril is not included in the premaxillae ; 

 both the anterior and posterior palatine foramina are well shown ; 

 its few and extremely large teeth and the more backward position 

 of the posterior nares and the narrowness of the region between the 

 temporal fossae approach the Crocodile of the present day, and 

 recede from the earlier Teleosaurian type. Mr. Hulke, in his 

 Presidential address to the Geological Society in 1884, said it may 

 be found convenient to remove Steneosaurus Manselii into a 

 separate genus or sub-genus; Sir R. Owen proposes to call it 

 Plesiosuchus Mansellii. The longer distance of the nares from 

 the outer nostril, the short stout jaws with few large teeth, the 

 premaxillaries meeting an inch and a-half anterior to the horizontal 

 nostril show an approach to Tertiary and existing Crocodiles. 

 The general equality of size of the tooth-crowns is typical of 



