8 FOSSIL REPTILIA OF THE 



The vertebra is Amphicoelian ; the neurapophysial suture is unobliterated ; it is from 

 the part of the trunk where the rib articulation has risen wholly above the centrum. 

 This element is 13 mm. in length; the non-articular surface is smooth and entire, 

 gradually and slightly expanding to the articular ends ; the one exposed being 

 subcircular, 10 mm. in diameter. 



Of the scutes preserved the largest are oblong, quadrangular, with a tooth-like 

 process from the anterior and outer angle, from the base of which is continued a raised 

 smooth tract along the anterior border, from 4 to 3 mm. in breadth. The breadth of the 

 entire scute is 17 mm. ; tlie length is 35 mm. Some smaller scutes are pentagonal. 



We have here, therefore, evidence of an Amphicoelian Crocodile, with the dermal 

 armour after the type of that of Goniopholis, but generically distinct by the characters of 

 the mandibular dentition. If the dentary bone constituted three fourths the length of 

 the mandible this may be reckoned to have been about 6 inches in length, and the entire 

 Crocodile may have been 6 feet in length. 



The portion of mandible of which the under surface of the dentary and splenial 

 elements are exposed, forming the subject of fig. 6, Plate II, is shown by certain teeth 

 in place and others scattered near in the same slab, to belong to the same genus and 

 species as that represented by fig. 1, and to have come from an individual of similar size. 

 Both are the largest evidences of Nannosuchus shown in the numerous series of Reptilian 

 fossils from the portions of the ' Feather-bed ' formation now under review. 



The symphysis, 21 mm. in longitudinal extent, forms a fifth part of the preserved 

 extent of the dentary ; the breadth of this part of the jaw is 30 mm. ; that behind the 

 symphysis is 27 mm. The rami, as far as they are preserved, diverge to a breadth of 

 70 mm. 



The alveolar part of the symphysis describes an incisive convexity, and the sockets 

 indicate one or two teeth of larger size and thicker proportions than those of the rest of 

 the dental series. The crowns of two of these teeth, which had become detached, are 

 fortunately preserved, near the fore part of the jaw. The largest (fig. 7, magn.) represents 

 the ' anterior canine,' and is the homologue of fig. 1 c and fig. 2, magn. It shows the well- 

 marked characteristics of that tooth in Nannosuchus, and, besides the difl'erence of sculptur- 

 ing, the crown is more strongly curved than in Goniopholis or Petrosuchus. The second 

 detached tooth near the incisive alveoli shows both root and crown. The latter is but 

 half the length of that of the ' canine ;' more of the convex side is exposed than in fig. 2 ; 

 it is traversed by fine longitudinal ridges. The teeth which are in place show a smaller 

 size and more slender pointed crown. There is no evidence of any tooth equalling in 

 size the largest of the symphysial or incisive series. 



The numerous minute circular pits sculpturing the symphysial expansion change, as 

 in the specimen (fig. 1), to coarser and larger longitudinal impressions as the rami 

 recede and pass backward ; and the surface near the alveolar border showing the feeble 

 molary convex curve is smooth. 



