494 Senry Woodward — Old Land-surfaces. 



the gigantic Pterodactyles and the turtle) of the proximity of land. 

 In the Chalk Marl of Folkestone a Dinosaurian allied to Igiianodon,^ 

 has also been discovered ; and in the Cambridge Greensand the rare 

 remains of birds, besides abundance of Pterodactyles, Cheloniee, and 

 other reptilia, evidence littoral conditions. 



At the base of the Neocomian series — and included in it by Mr. 

 J. W. Judd ■■* — we come to the great Wealden formation, remarkable 

 for its gigantic Dinosauria, on which so much new light has lately 

 been thrown by Prof. Huxley, Mr. J. W. Hulke, and others.^ Here 

 we also meet with entire beds of minute Gyprides, whilst the cele- 

 brated band of stone in this formation known as Petworth marble, 

 composed entirely of the shells of Paludinm, together with Vnio, 

 ■Cyclas, Oyrena, etc., mark its freshwater origin. The Lepidotus 

 Mantelli, a jSne Ganoid fish, from the Wealden, with large rhom- 

 :boidal scales, was probably (like the great Gar-pike of the American 

 rivers) a freshwater fish. Chelonias (represented by Trionyx and 

 Emys) and a Pterodactyle are also found ; whilst ConiferEe Cycadean 

 plants and Arborescent Ferns, with others of lowlier growth, 

 complete the Wealden landscape. 



In the uppermost member of the Oolitic group, we again find, at 

 Purbeck, in Dorsetshire, evidence of a land-surface of the highest 

 interest marked by remains of above ten genera and twenty-five 

 species of Mammalia ! * together with some six or seven genera of 

 freshwater MoUusca — Cyprides, Turtles, and Fish, and about forty 

 species of Insects ; whilst a large number of small land-Eeptilia 

 remain undescribed. 



In the Lower Purbeck we also meet with a most interesting 

 geologic relic in the Portland Dirt-bed, with its old vegetable soil and 

 its silicified trunks of Cycadese and stools of Coniferse still preserved 

 in situ. We have here also evidences of repeated changes of level, 

 causing alternations of fresh and marine conditions, as shown by the 

 successive beds and their fossil contents. 



Passing on to the Kimmeridgian series, we have bituminous shales 

 and impure coal-seams, forming in all a mass of strata several 

 hundred feet in thickness, marked also by the remains of one of the 

 largest Saurians known, the gigantic Cetiosaurus, from near Oxford, 

 and by nu.merous Teleosaurians and other Crocodilian and Gavial- 

 like reptiles. The Solenhofen-stone again reveals an Oolitic long- 

 tailed bird, the Archceopteryx, numberless Pterodactyles, both of the 

 long and short-tailed type; together with lacertilian reptiles and 

 countless insects, telling of an Oolitic land rich in Coniferse and 

 other trees and plants, and swarming with animal existences. 



Passing over a series of marine beds, we come again, in the Stones- 

 field slate, upon abundance of Insect-life ; upon remains of the great 

 Megalosaurus and Pterodactyles ; three genera of Mammalia, and a 



1 Acanthopholis horrichis, Huxley. Geol. Mag., 1867. Vol. IV., p. 65. PI. V. 



2 See Quart. Joum. Geol. Soc, vol. xxvi., 1870, p. 326. 



2 Iguanodon, Hylceosaurus, Sypsilophodon, Strcptospondylus, Megalosaurus, etc. 

 * See Prof. Owen's Monograph ou "the Fossil Mammals of the Mesozoic Forma, 

 tions." Pal. Soc. vol. xxiv. 1871. 



