6 FOSSIL REPTILIA OF THE 



laniary convexity succeeding the incisive one, togetlisr with greater number and the 

 shape of the teeth of Nannosuchm (PL II, figs. 8 and 9) offer a more striking contrast 

 with the mandible and teeth of Brachydeds. 



No specimens have been brought to hght which show characters of Brachjdedes 

 minor on a larger scale than is represented by the mandibular ramus above described. 



Genus — Nannosuchus,^ Owen. 



Species — Nannosuchus gracilidens. Plate II, figs. 1 — 10 ; Plate III, figs. 1 and 2. 



In this genus the teeth have long, slender, sharp-pointed crowns, slightly recurved, 

 mostly sub-circular in transverse section, impressed by a few linear or narrow and shallow 

 grooves. The dental series is pretty uniform as to size and shape of crown, but less so 

 than in the Teleosaur and Gavial ; the teeth are also less numerous and wider apart. 



The claim to generic distinction indicated by the armature of both upper and lower 

 jaws was established by an additional dental character revealed in the following 

 specimen. 



The fore part of the mandible (Plate II, fig. 1) exhibited a tooth in situ (fig. 1 c and 

 fig. 2 enlarged), answering to that termed the 'anterior canine' in Crocodilia, but 

 presenting characters which I had not before observed in those or other Beptilia. 



The crown is long in proportion to the basal breadth, conical, recurved, and pointed. 

 It is traversed along the middle of the outer surface by a ridge, or rather a low angle of 

 the enamel, simulating a ridge ; between this and the trenchant hind border is included 

 one third of the outer surface of the crown. This tract is smooth, and, transversely, is 

 feebly depressed or concave, giving a trenchant character to the hinder longitudinally 

 concave edge of the crown. The two thirds of the outer, transversely convex, surface of 

 the crown is traversed by close-set linear grooves, and intervening ridges, which mostly 

 subside at the apical half of the crown, leaving about one third of the apex smooth. 

 This tooth appears to be the fourth counting backward ; the length of the crown is 

 10 mm., the basal breadth 3 mm. An enlarged view is given of the outer side of the 

 crown in fig. 2. 



The foremost tooth, also preserved (fig. 1, i), shows a coronal length of 5 ram., a 

 basal breadth of 1 mm. 



The crown of a fifth tooth rises close behind that of the fourth, with a basal breadth 

 of 2 mm, and a length of 5 mm.; it is conical, but is straight. The outer side, 

 uniformly convex, is traversed along the basal half by fine ridges and intervening grooves ; 

 it may be that the whole of this crown has not emerged. 



^ viii'toi, dwarfish, loDj^vs, an Egyptian name of the Crocodile. 



