SUPPLEMENT (No. IX) 



TO THE 



MONOGRAPH 



ON 



THE FOSSIL EEPTILIA 



OP 



THE WEALDEN AND PUEBECK EORMATIONS. 



(GONIOPHOLIS, BRACHYDECTES, NANNOSUCHUS, THERIOSUCHUS, 



AND NUTHETES.) 



Order. CBOCODILIA. 



The subjects of the present ' Supplement' are from the same division ('Eeather- 

 bed ') of the fresh-water deposits of the Middle Purbeck series as the Mammalian 

 fossils described in the under-mentioned volume,^ and were disinterred by the skilful 

 and enterprising explorer of that geological series, Samuel Husband Beckles, Esq., 

 F.R.S., to whom the discovery of most of those fossils is due. 



The whole of Mr. Beckles' gatherings from the Purbeck shales having been acquired 

 by the British Museum, many slabs with indications of organic remains have been 

 carefully worked out, and the chief parts of the subjects of Plates I — IV have thus 

 been brouglit to light. 



At the first aspect, detecting in the scattered groups of scutes specimens showing the 

 peg (PI. IV, fig. 3, a) and groove (ib., fig. 4, b), it seemed as if remains of some young 

 specimens of Goniopliolis were so exposed. The condition, however, of two of the 

 skulls (PI. Ill, figs. I and 3) enabled a comparison to be made which determined their 

 specific and, by their dentition, generic distinctions from both GoniophoUs qw^l Petrosuchus. 

 The number of maxillary and mandibular specimens, of which several are figured in 

 PI. in, exemplified a degree of constancy in size which begat a conviction that such was a 

 character of the species; and, diminutive as were the Reptilia which have supplied the 

 subjects of both plates, their characters were indisputably those of the Order Crocodilia. 

 One of them, by the size and shape of certain teeth, came nearer to Goniopholis, another 



^ ' Monograph of the Fossil Mammalia of the Mesozoic Formations ;' in the Volume of the Palaeonto- 

 graphieal Society for the year 18/0. 



10 



