428 BRITISH FOSSIL REPTILES. 



the apical half of the crown, to which they give somewhat of a trenchant character 

 (PI. 12, fig. 4). At the hack part of the series the crown becomes obtuse (Pi. 7, 

 fig. 2) ; as it also does in the Crocodilus HastingsicB (' Crocodilia,' PI. 1 b, fig. 1), 

 and in the Groc. Spenceri (PI. 3, a, fig. 12). 



On these characters the present genus and species were founded in my ' Report 

 on British Fossil Reptiles.'* 



In the British Museum is preserved the split slab of Purbeck limestone, quarried 

 near Swanage, Dorsetshire, containing dislocated parts of a skeleton of a reptile, 

 determined by the two teeth, fortunately retained in the part of the lower jaw 

 preserved, to belong to the Goniopholis. 



The first character which attracts the palseoutologist's attention, in this remarkable 

 specimen, is that which the numerous large, bony, dermal plates or scutes afi'ord 

 (PI. 7. d). These are scattered irregularly over the slab, and in their number and 

 relative size bring the species much nearer to the extinct Teleosaurs than to any of 

 the existing Crocodiles ; they diff'er, however, from both the dorsal and ventral scutes 

 of the Teleosaur in their more regular quadrilateral figure ; they are longer in propor- 

 tion to their breadth than most of the Teleosaurian scutes, and are distinguished from 

 those of all other Crocodilians, recent and fossil, that I have yet seen, by the presence 

 of a conical, obtuse process (PI. 1, figs. 1 and 2, a) continued from one of the angles 

 vertically to the long axis of the scute ; analogous to the peg or tooth of a tile, and 

 fitting into a depression on the under surface of the opposite angle (ib., fig. 1, b) of the 

 adjoining scute ; thus serving to bind together the plates of the imbricated bony 

 armour, and repeating a structure which is highly characteristic of the large bony 

 and enamelled scales of many extinct ganoid fishes. Some of the scutes in the 

 Swanage specimen are 6 inches in lengtli and 2^ inches in breadth. 



The exterior surface of the scute (PI. 8, fig. 2) is impressed by numerous deep, 

 round, oblong, or angular pits, from two to four lines in diameter, and with 

 intervals of about two lines, formed by convex, reticularly disposed ridges of the 

 bone ; but a larger proportion of the anterior part of the scute is overlapped by 

 the contiguous scute that in the Teleosaur, and this part is smooth, and thinner than 

 the rest of the scute. The whole of the inner surface of the scute (ib., fig. 1) is smooth, 

 but on close inspection it is seen to be everywhere impressed by fine, straight lines, 

 decussating eacli other at nearly right angles, and indicating the structure of the 

 corium in which the scutes were imbedded. Thus, from the size and strength of these 

 dermal bones, their degree of imbrication, and the structure for interlocking, we 

 may conclude that the Goniopholis was better mailed than even the extinct Teleosaur, 

 which Cuvier regarded as " I'esp^ce la mieux cuirassee de tout le genre. "f 



In the slab in question the vertebras (PI. 7, v, v) were unfortunately all at right 



* 'Reports of the British Association,' 18-11, p. G9. 

 t ' Ossemens Fossiles,' torn, v, pt. 2, p. 1, 139. 



