A HISTORY OF SUSSEX 



interesting to note the occurrence at Bracklesham of a species, Arius 

 egertoni, belonging to an existing tropical genus, this species also occur- 

 ring in the Belgian Eocene. Among the mackerel family [Scombrida) 

 remains of an undetermined species of the extinct genus Scotnbrhamphodon 

 occur at Bracklesham, and these deposits have likewise yielded specifically 

 indeterminable vertebrae referable to the genus Xiphiorhynchus, an extinct 

 type of sword-fish. Another Bracklesham sword-fish, Histiophorus 

 eoccentcus, belonging to a genus still living, has been recently named by 

 Dr. Smith Woodward on the evidence of a ' sword ' in the British 

 Museum. Lastly, we have Platylcemus colei, an extinct generic type of 

 bass [habridce] described by Dixon on the evidence of specimens of the 

 dental plates from Bracklesham, and at present unknown elsewhere. 

 Dr. Woodward describes it as ' an extinct genus known only by the 

 pharyngeals, each nearly or completely covered by a crushing plate, 

 which consists of coarse vascular dentine invested with a very thin layer 

 of gano-dentine.' 



The Lower Eocene Bognor beds — the equivalent of the London 

 Clay — seem to be exceptionally poor in vertebrate remains. They have 

 however yielded an imperfect turtle-shell, which was made the type of 

 a species by Owen, under the name of Chelone declivis, although it has 

 since been provisionally identified ^ with one from the London Clay of 

 Sheppey, now known as Argillochelys convexa. Vertebrae apparently 

 referable to the long-nosed Lower Eocene crocodile known as Crocodilus 

 spenceri also occur at Bognor. 



The reptiles of the Sussex Chalk are not numerous, although some 

 are of considerable interest. The great marine lizards known as 

 Mosasauria are represented by Liodon anceps, a species which also occurs 

 in the Chalk of Norfolk and Essex. A second species of the group has 

 been described on the evidence of remains (now in the Brighton 

 Museum) by Owen under the name of Mosasaurus gracilis. These 

 remains were at one time considered by Dr. Smith Woodward to in- 

 dicate a fish of the genus Pachyrhizodus rather than a reptile, but subse- 

 quent investigation has convinced the same palaeontologist * that the 

 original determination was correct, although it does not follow that the 

 species belongs to the genus Mosasaurus. The crown of another 

 mosasauroid tooth from the Chalk of the county has been provisionally 

 assigned by the present writer ^ to the American Cretaceous genus 

 Platecarpus. The most interesting of the Sussex Chalk lizards is how- 

 ever Dolichosaurus longicollis, a long-necked, snake-like, marine type also 

 occurring in the Chalk of Kent ; in Sussex its remains have been found 

 in Southeram pit, near Lewes. Remains from the Chalk of Washington 

 near Worthing have been regarded as those of a small lizard, under 

 the name of Coniasaurus crassidcns. Another presumed lizard, Rbaphio- 

 saurus subulidens, is now definitely known to have been named on teeth 

 of a fish. 



' Cat. Foil. Rcf't. Rill. Mm. Hi. 48. » Cot. Fois. Fish. Brit. Mm. iv. 45. 



■■' Cut. Foil. Rr/>t. Brit. Mns. i. 271. 



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