A HISTORY OF KENT 



eagle-ray, Myliobatis goniopleurus and M. toliapicus, described on the 

 evidence of their roller-like dental plates from Sheppey. An extinct 

 species, Rhinoptera daviesi, of an allied living genus, is known by a single 

 specimen of the dentition in the British Museum. The long-tailed 

 eagle-rays, whose dentition differs from that of Myliobatis by having no 

 lateral plates, are represented in this formation by Aetobatis irregularis, a 

 species described on the evidence of Sheppey specimens but also 

 occurring in other Eocene deposits. 



Among the sharks, the existing genus Notidatius, characterized by 

 its comb-like teeth, is represented at Sheppey by N. serratissimus, a 

 species somewhat widely spread in the Eocene, but typically from that 

 locality. Of sharks allied to the existing porbeagle the widely spread 

 Lamna macrota, Otodus obliquus, Odontaspis elegans, and O. cuspidata have 

 left their sharply pointed teeth in the clay of the Isle of Sheppey, but 

 neither species is typically Kentish ; the species of Odontaspis also occur 

 at Heme Bay. A small relative {Carcharodon subserratus) of the great 

 Rondeleti's shark of modern seas is typified by a single tooth from 

 Sheppey in the collection of the British Museum. 



Of fishes allied to the existing chimera, or king of the herrings, 

 dental plates referable to two extinct genera are not uncommon at 

 Sheppey. One of the species, Edaphodon bucklandi, was first described 

 from the Middle Eocene of Sussex, but the second, Elasmodus hunteri, 

 although also common to the Middle Eocene, is typified by a Sheppey 

 specimen in the Museum of the Royal College of Surgeons. 



Very interesting is the occurrence in the London Clay of Sheppey 

 of dermal bones of a sturgeon, which have been provisionally assigned 

 to the typical living genus under the name of Acipenser toliapicus \ they 

 afford the earliest known evidence of true sturgeons. 



Of the pycnodont ganoids — those hard-scaled extinct fishes with a 

 pavement of bean-like crushing teeth in the mouth — the species Pycnodus 

 toliapicus and P. bowerbanki are both peculiar to Sheppey, the latter 

 being apparently only known by the type specimen in the British 

 Museum. 



To a more modern type of fish — the Elopidce, relatives of the 

 herrings — belongs a fossil in the British Museum from Sheppey which is 

 provisionally assigned to the living genus Elops. Two extinct species, 

 Megalops priscus and M. oblongus, of the other existing genus of the 

 family, are peculiar to the Sheppey deposits ; the same being the case 

 with Esocelops cavifrons, the sole representative of its genus, and known 

 only by a couple of specimens in the national collection. In the alUed 

 family Albulidce, the typical genus, of which one tropical species still 

 survives, is represented by Albula oweni in the Sheppey deposits, a species 

 apparently also occurring in the Middle Eocene of Belgium. The 

 genus and species Brychcetus muelleri, belonging to the family Osteoglossida, 

 now characteristic of the southern hemisphere, have been described 

 recently by Dr. Smith Woodward on the evidence of remains from 

 Sheppey in the British Museum. In the herring family {Clupeidce) re- 



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