V/EAVEk: INVERTEBRATE PALEONTOLOGY AND HISTORICAL GEOLOGY 595 



on the Subappenine fossils. These were described and illustrated and a record 

 was made of their exact occurrence within the different strata from which they 

 were collected. Attention was called to the biological similarities of some of the 

 species to those now living in the Mediterranean and also to certain forms from 

 the Paris Basin. Other investigations by Omalius d'Halloy in Belgium and other 

 parts of southern Europe and Germany presented evidence for future corre- 

 lation of the Tertiary deposits from different parts of the continent. 



Among the earlier publications dealing with fossils and rocks of Tertiary 

 age was the work by Conybeare and Phillips in 1822 in which the sedimentary 

 deposits in Great Britain above the Cretaceous were classified in ascending order 

 as the Plastic Clay, London Clay, Freshwater Beds, and the Upper Marine For- 

 mation consisting of the Bagshot Sands and the Crag. This work, along with 

 numerous others including the description of fossil mollusks by the Sowerbys, 

 afforded material for a comparison of the British Tertiary fossils with those 

 described by Deshayes in 1824-1837 from the Paris Basin, Italy, and other parts 

 of Europe. Deshayes recognized an increase in the proportion of living species 

 among the successive faunas from earliest to latest Tertiary. During this time 

 Charles Lyell, who had traveled extensively in France, Italy, and other parts 

 of Europe, studied the Tertiary outcrops and also the fossil collections that had 

 accumulated in the museums and universities. Working independently, H. G. 

 Bronn made detailed investigations of the Tertiary rocks and faunas of Italy 

 and also observed the increase in the percentage of living species and genera in 

 the younger beds. Lyell, after considerable association with Deshayes in Paris, 

 correlated the deposits of France with those in the south of England and, influ- 

 enced by the increasing percentage of living species from the base to top of the 

 Tertiary, established new terms for the major divisions. In the third volume of 

 his Principles of Geology published in 1833 he introduced the names Eocene, Mio- 

 cene, Pliocene, and Recent. In 1846 the name Pleistocene was introduced by 

 Forbes to include the uppermost Pliocene of Lyell and deposits of glacial origin. 

 After 1850 the additional divisions of Paleocene and Oligocene were added by 

 other workers. 



Geological and paleontological research in eastern North America during 

 the first half of the nineteenth century was carried on largely under the auspices 

 of the newly established state geological surveys and by individuals associated 

 with a few universities and academies of sciences. Ebenezer Emmons, after a 

 study of the rocks in New York State, classified them in upward succession as 

 tlie Crystalline complex, the Taconic system of greatly disturbed beds, the New 

 York system, and the Red Beds. The New York sj^stem consisted of nearly 

 horizontal beds of sandstones, shales, and limestones, which he subdivided into 

 the Champlain, Ontario, Ileldeberg, and Erie groups. A report published by 

 James Hall of the New York Survey in 1843 subdivided the New York system 

 into twenty-nine groups. The Paleozoic rocks of Pennsylvania were investigated 

 by H. D. and W. B. Rogers, who in 1843 described their composition, lithology, 

 thickness, and geologic structure. The coal in the upper beds was considered as 

 having been formed from peat bogs occurring on the surface of an extensive 

 plain which from time to time suddenly passed slightly below and above the 

 level of the sea. The Rogers recognized the folded character of the Appalachian 

 Range and considered its deformation to have taken place after the deposition 



