﻿2 



FOSSIL REPTILIA OF THE 



centre ; a number of short ridges and clefts radiate from the raised part of the border of 

 the temporal outlet ; but all these accentuations of the surface are rather feeble. 



As I know of no corresponding specimen of a skull of any Wealden Crocodilian like 

 the present, and as it offers generic modifications of parts which are comparable with 

 Crocodilian s of older and newer formations, I propose to describe the specimen as 

 representing a new genus and species under the name of " Hylceocltampsa vectiana." 1 



The occipital surface (Plate II, fig. 23), excluding therefrom the tympanies, 28, and 

 pterygoids, 24, is of a triangular form, with the base upward ; the apex is pierced by the 

 foramen, v. The breadth of this surface, taken at the mastoidean angles, 8, 8, is, to so much 

 of the vertical diameter as includes the foramen,/, as three to one. The basioccipital, i, 

 contributes the middle four fifths of the condyle, the upper angles of which hemispheroid 

 tubercle, due to the exoccipitals, are broken off. The centre of the condyle is feebly 

 impressed ; it projects, and is, as it were, sub-pedunculate. The basioccipital curves from 

 the condyle forward and downward, then descends vertically to the foramen, v , and is ridged 

 along the mid-line. The extent of the occiput below the foramen magnum,/ ; exceeds the part 

 above the foramen. The exoccipitals, 2, are the largest elements of this cranial segment ; 

 they meet above the foramen, excluding the superoccipital, 3, therefrom for an extent of 

 nearly three lines. The suture appears to be continued upward through the superoccipital, 3 ; 

 but this may be due to fracture. The superoccipital develops a tuberosity at each upper 

 angle, near its junction with the mastoid, 8. Each exoccipital swells at its outer border 

 into two tuberosities, representing the paroccipitals of Chelonia, and contributing to the 

 articulation for the tympanic, 28. The direction of the bilobed paroccipital border, 4, is 

 oblique from above downward and inward. The tuberosity forming the angle of the 

 mastoid, 8, projects distinct from the upper paroccipital one, 4. 



In the relative extent of the paroccipital tuberosities and in the direction of their 

 border Hylaoc/iampsa resembles Teleosaurus, and differs from Crocodihs, in which the 

 masto-paroccipital border extends from above downward and outward (ib. fig. 4), making 

 the greatest breadth of the occipital surface to be at the paroccipitals, not at the mastoids. 



There is no vacuity between the mastoid and superoccipital ; a linear suture, slightly 

 concave upward, alone divides them on the occipital surface. 



The articular surface of the tympanic, 28, projects as usual, backward, beyond the 

 plane of the occiput ; the medial half only of that surface is preserved in the present fossil ; 

 it is almost vertical and very slightly convex. 



The upper platform of the cranium behind the orbits (Plate II, fig. 24) is subquadrate, 

 with the anterior angles rounded off. It is perforated by the pair of upper temporal 

 openings, t, which are oblong-ovate, with the outer border almost straight, the inner one 

 curved, and with the hinder or basal border slightly raised; the anterior border is 

 depressed and continued upon the side of the cranium proper, forming the inner wall of 



1 Gr. v\t}, wood or weald ; ya^a, an Egyptian name of the crocodile. The specific name relates to 

 the locality of the fossil. 



