Page:VCH Surrey 1.djvu/69

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PALEONTOLOGY O. mantelli have likewise been recorded from the county. But this by no means exhausts the list of Surrey Cretaceous sharks, the British Mu- seum possessing teeth of Corax falcatus and three vertebrae of Cetorhinus duponti from the chalk of Guildford. Passing on to the chimaeroid fishes, a tooth from the chalk of Dor- king in the British Museum indicates the occurrence of Edapbodon agassizi in the county. Two other types are Plethodus oblongus and P. pentagon, the former represented by a skull and the latter by teeth from the Dorking chalk. Among the so-called ganoid fishes, the well-known Macropoma mantelli is represented in the same collection by a crushed head and dorsal fin from the chalk of Dorking as well as by vertebra? from Guildford. The well-known rhomboidal scales and button-like teeth of Lepidotus pustulatus occur in the lower greensand of Godalming; while the smaller ornamented crushing teeth of Gyrodus cretaceus have been obtained from the chalk of St. Catherine's Hill and Croydon. Another Cretaceous ganoid found in the county is Neorhombolepis punc- tatus, of which the national collection contains scales from the lower chalk of Dorking. To a family (Amiidce) now represented only by Amia calva of the freshwater of North America belongs Protosphyrcena ferox, a Cretaceous fish with large spear-like teeth long known under the name of Saurocepbalus lanciformis ; teeth of this type have been found in the chalk of Guildford. Yet another form is Tomognatbus mordax, a fish with large teeth fixed to the jaws, of which skulls have been obtained at Dorking. Among fishes of a more essentially modern type, the extinct Cre- taceous family Ichthyodectidce, which includes some species of gigantic dimensions, is represented in the Dorking chalk by jaws of two species of the typical genus Icbtbyodectes, namely /. elegans and 7. lewesiensis. To the same family belongs the fish known as Enchodus lewesiensis, of which remains have been recorded from the chalk of Shalford and Guildford. An allied type is Prionolepis angustus, typically from the chalk of Sussex, but also represented by scutes from that of Dorking. To another family the Elopidce belongs Osmeroides lewesiensis, likewise a Sussex Cretaceous fish, of which remains occur both at Shalford and Guildford. Another Sussex type is Aulolepis typus, of which certain re- mains have been found in the Dorking chalk. Neither are the so-called barracudas wanting from the Cretaceous beds of the county, scales of an extinct generic type termed Cladocyclus lewesiensis occurring in the chalk of Dorking as well as in that of Sussex. The perch-like fishes, which only date from the Cretaceous epoch, have at least three representatives in the county, one of which (Hoplopteryx lewesiensis^ belongs to an extinct, while the other two (Eeryx radians and B. microcephalus] are assigned to a still living genus. Of the first- named remains have been obtained at Guildford, of the second at Dor- king, and of the third at Reigate. The Lower Tertiary deposits of Surrey appear to be poor in fish- Si