PALAEONTOLOGY 



are specimens of the dentition of the extinct genus Phyllodus, referable 

 to the three species P. speciosus, P. hexago?ius and P. toliapicus. A frag- 

 ment of a fin-spine from Foxhall is referred by Mr. E. T. Newton to 

 the extinct cat-fish Arius egertoni, whose typical horizon is the Middle 

 Eocene of Sussex. Of the pycnodont ganoids, or those with rounded or 

 oval crushing teeth, specimens from the Crag have been assigned to the 

 genera Pycnodus, Gyrodus, Pisodus and Lepidotus ; those belonging to the 

 first and third being probably derived from the London Clay and the 

 others from still older formations. Dental plates' of fishes allied to the 

 living chimasra or king-of-the-herrings are also met with in the Red 

 Crag, and have been assigned to the Eocene genera Edaphodon and 

 Elasmodus. To the same group belongs a fragment of a fish-spine from 

 Woodbridge, now in the British Museum, which has been referred to 

 the Eocene Ccelorhynchus rectus. 



Allusion to ' derived ' teeth of sharks belonging to the genus 

 Odontaspis has been made in an earlier paragraph. In addition to these 

 occur larger teeth belonging to the Eocene shark known as Otodus obli- 

 qiius. The large roller-like dental plates of eagle-rays of the genus 

 Myliobatis, occasionally met with in the Red Crag, have for the most 

 part been identified with the Eocene species M. dixoni and M. toliapica. 

 Others belong to the allied genus /Etobatis. The Ipswich Museum 

 possesses a few fragments of the well known crushing teeth of the 

 Cretaceous genus Ptychodus, which have been identified with P. polygyrus, 

 so abundant in the English Chalk. Lastly, fragments of teeth from 

 Woodbridge indicate a saw-fish [Pristis), doubtless identical with a lower 

 Eocene species. 



Of far more interest than the above derived specimens are certain 

 fossils obtained in the year 1839 by the late Mr. W. Colchester of 

 Ipswich in the Lower Eocene sand of Kingston near Woodbridge, some 

 of which are described in Owen's British Fossil Mammals and Birds. 

 Among these a fragment of a lower jaw, showing one entire cheek tooth, 

 has been referred to an opossum with the name Didelphys (?) colchesteri ; 

 but the real affinities of the specimen must remain undecided. Another 

 mammal, typified by two cheek teeth of the upper jaw, was named by 

 Owen Hyracotherium cuniculus, as these teeth, although smaller, appeared 

 generically identical with those of H. leporinum. A fragment of the 

 lower jaw, with two teeth, of the former species included among 

 Mr. Colchester's collection was at first regarded as indicating a monkey, 

 and accordingly named Macacus eoccenus. Another mammalian tooth 

 from Kingston is figured by Owen (op. cit. p. 17), and provisionally 

 regarded as that of some kind of bat. 



A fragment of a jaw from Kingston described by Sir R. Owen as 

 Lacerta (?) eocana, appears to be certainly reptilian, although its precise 

 generic determination is probably impossible. Certain fish-scales from 

 Kingston presented to the British Museum by the Rev. J. Middleton 

 in 1854, are referred by Dr. Smith Woodward to the genus Lepidosteus, 

 now represented by the bony pike of the rivers of North America. From 



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