52 ME. E. W. HOOLEY ON THE SETJLL AND [Feb. I907, 



ascribed by him to Goniopholis crassidens, but both skulls un- 

 doubtedly belong to the species G. simus. 



There is a feature on the skull of the type-specimen which is not 

 noted by either of these authors. A bony ridge, from the inner 

 anterior border of the orbits, passes across the frontal bone in a 

 curve, developing in the centre into a prominent eminence 6 mm. 

 high, which in life must have been slightly higher, as the apex is 

 gone. It is well defined, and has not been caused by crushing. 



On enquiry of Prof. Louis Dollo, I was informed by him that the 

 skull of Goniopholis simus in the Musee Royal d'Histoire Naturelle 

 de Belgique, at Brussels, shows no traces of the crest. However, 

 this keel is found in Nannosuchus gracilidens as well, and is also not 

 noted by Owen. It is interesting to observe that it is also present 

 in the recent caimans and the North American alligator, but not iu 

 any of the crocodiles that I have examined. Thus it appears in 

 Caiman latirostris, sclerops, niger, latifrons, and Alligator mississip- 

 piensis ; while it is absent in Crocodilus niloticus, palustris, porosus, 

 rohustus, americanus, and in the gharials. 



In 1879 l Owen described another species under the name of 

 Goniopholis tenuidens, from the anterior portion of a mandible, 

 from the Middle Purbeck of Durleston Bay. He estimated the 

 jaw of Goniopliolis crassidens to have measured about 2 feet in 

 length, and G. tenuidens about a quarter of the size ; and he differ- 

 entiated the latter from G. crassidens and from G. simus by this and 

 the greater slenderness of the teeth. 



To four vertebrae, Owen gave the name of Goniopholis carinatus. 

 He figured them, 2 but gave no description. 



The fossils from which these four species of Goniopholis have 

 been formed appear to be the only specimens from Britain that 

 have been hitherto described. 



Through the kindness of Dr. A. Smith "Woodward, and Mr. E. J. 

 Baily, of Battle (Sussex), who forwarded the specimen to the Natural 

 History Museum, I have been enabled to study the skull of a 

 Goniopholis, discovered by the latter gentleman in the Purbeck 

 limestone near Battle. The skull is very much flattened, and 

 portions of the upper jaw alone remain, much apparently having 

 been destroyed at the moment of discovery. 



The premaxillse, as far as 13 mm. from the tip of the snout, are 

 entire ; but there a small section is missing. The greater part of the 

 maxillae and nasals, minus their posterior ends, are preserved. The 

 prefrontals, lachrymals, and all other bones are absent, except the 

 hinder portions of the frontal and postfrontal, and the anterior of 

 the parietal. These latter, and the impress left on the matrix by 

 what is lost, determine the supratemporal fossa to be subquadrate, 

 and only slightly larger than the orbits. The articular ends of the 

 quadrates remain. 



1 ' Monograph of the Fossil Eeptilia of the Wealden & Purbeck Formations ' 

 Suppl. ix (Palasont. Soc. 1879) p. 2 & pi. i. 

 5 ' British Fossil Eeptilia' 1849-84, vol. ii, pi. xiv. 



