7J0 De la Beckers Geological ManuaL 



attention of the young geologist. Those fossil organic remains 

 that mark a change in the condition of the surface of our 

 planet, as from sea to fresh water, or from fresh water to dry 

 land, are particularly deserving of notice, and ttlso the new 

 forms of organic life which indicate a great change in th^, 

 character of the ancient inhabitants of the globe ; but it cdn 

 be of little interest to the student to know the names of 800 

 species or varieties of marine shells, no way remarkable 

 for their structure, occurring in a formation universally ad- 

 tnitted to be marine. Correct lists' of the fossils in any one 

 formation, made by residents in different districts, like those 

 bf Mr. Mantell of the chalk fossils in Sussex, and Mr. Phillips 

 oi the chalk fossils in the eastern part of Yorkshire, are 

 exti'emely interesting to well instructed geologists, who can 

 appreciate their value, and the bearings of the evidence which 

 they furnish; but such lists are not suited for an introductory 

 work, much less so are lists collected from various authors, 

 ftiany of whdm have never themselves examined the beds 

 fi^dm which the fossils were' takeni^»^"^f. Wii'^nol ^guuiugiioD to 

 J^ 'Section the third contains an accbuilf Bf tvh'ati^ sdmev\^hitt 

 Quaintly styled the erratic block group; which comprises the 

 loose blocks of rock and beds of gravel, scattered over various 

 countries, the evident proofs of the transporting power of 

 water. In this section is comprised also some account of 

 bone caverns and osseous breccia. At section 4. comtnences 

 title account of the tertiary strata, or what the author is pleased 

 {o style " the supercretaceous group." We greatly object to 

 the introduction of new names, in a science already overbur- 

 dened with different nomenclatures. The term supercreta- 

 ^jebus has no advantage over the received term tertiary^ which 

 fs "always understood to designate the deposits of strata riior^e 

 'decent than chalk; but these strata do not nniversally rest 

 ,on chalk, as the term supercretaceous would imply. The 

 tertiary strata are in many respects highly interesting to the 

 geologist, but contain few substances of value to a nation. 

 tn the present work they cover 73 pages, while the coal 

 measures, of great geological interest, and possessing the great 

 sources of national wealth, coal and ironstone, are dismissed 

 in a few leaves, and these chiefly occupied with the mountain 

 limestone (the transition limestone of foreign geologists), 

 which the author associates with the coal measures. The 

 chalk and oolite formations, including the Weald clay and 

 sandstone, occupy 122 pages. The red sandstone group is 

 described in 22 pages : this we consider as the best digested 

 and arranged section in the book. The rocks denominated 

 by other geologists primary, are described in a very brief 

 and summary manner; and metallic veins and repositories, 



