26 INTRODUCTION. 



Survey, whose Maps and other publications describe the 

 country in detail ; while the work of the pioneers is followed 

 up by an ever-increasing band of geologists. 



Broadly speaking, the northern and western parts of 

 England and the greater part of Wales are formed of the 

 older rocks known as Primary or Palaeozoic. These were 

 considerably folded and disturbed, before the newer rocks 

 were laid down. Resting on their upturned edges, or abutting 

 against them, lie the Secondary strata which form a group 

 dipping generally in a south-easterly direction, so that in 

 passing from north-west to south-east we come successively 

 on higher and higher beds, from the Lias, which stretches 

 from Lyme Regis in Dorsetshire to Whitby in Yorkshire, to 

 the Chalk which runs from Dorsetshire and Hampshire to 

 Flamborough Head. The older Tertiary beds repose on the 

 Chalk in the irregular areas known as the London and 

 Hampshire Basins ; and they were together much disturbed 

 and denuded before the newer Tertiary or Pliocene strata were 

 laid down on the western borders of the German Ocean. 

 The Quaternary deposits form a distinct group scattered 

 irregularly over the country, and resting indifferently on any 

 of the rocks from the oldest upwards.^ (See Map and Fig. 3.) 



While Cuvier laid the foundation of the Palaeontology of 

 Vertebrate animals, and Lamarck that of the Invertebrates, 

 we are in this country indebted to the Sowerbys ^ and Parkin- 

 son ^ for the early illustration of our fossils. 



The number of British fossils, amounting to about 4450 genera 

 and 16,000 species (according to Mr. Etheridge), may well appal 

 those who would attempt to identify the fossils they collect ; but 

 the student, as a rule, must be satisfied with determining the 

 genus of any fossils he may procure, leaving the specific names to 

 those whose special work lies in some department of Palaeontology. 

 Access, however, to the splendid Monographs published by the 

 Palceontographical Society, or a comparison of his specimens with 

 those exhibited in the cases of some Museum, will often enable the 

 geologist to determine the species he has obtained.'* 



^ For the geology of particular counties, see the Geology of the Counties of 

 England and of North and South Wales, by W. J. Harrison, 18S2. See also 

 Geological Map of England and Wales, by A. C. Ramsay, which contains a 

 section on which Fig. 3 is based. 



- The Mineral Conchology of Great Britain, 1818-1829. 



^ Organic Remains of a Former World, 1804-1811. 



* See also Figures of Characteristic British Fossils, by W. H. Baily, vol. i. 

 PaL-eozoic, 1867-75 5 Charts of Characteristic British Fossils (1853), and of 

 British Tertiary Fossils (1868), by J. W. Lowry ; and Chart of Fossil Crustacea, 

 by J. W. Salter and Dr. Henry Woodward, 1865; Stratigraphical Geology and 

 Palc-eontology, by R. Etheridge, 1885. 



