Henry Shaler Williams. 685 



take it that there is nothing inconsistent in the view that 

 Catskill rocks were being deposited in the Appalachian 

 region at the same time that Chemung rocks were being- 

 formed over western New York areas and during the 

 reign of the Chemung faunas" (On the Fossil Faunas of 

 the Upper Devonian. The Genesee Section, 1887). 



Recurrent faunules have been traced by Williams 

 through a thickness of "about 2000 feet of sediments." 

 A "half-dozen fossils of particular species occurring 

 together" can not determine the stratigraphic horizon; 

 all they can do is to show that their time horizon is 

 "somewhere within one or two thousand feet of thick- 

 ness of strata." We are then forced to the conclusion 

 "that not only lithologic but paleontologic facts are 

 local." He states that the fossils undoubtedly are the 

 means on which we chiefly rely for determining that kind 

 of equivalence which is called contemporaneity and 

 homotaxy ; but it must not be overlooked that species and 

 genera of fossils may be extremely long ranging (Bear- 

 ing of some new Paleontologic Facts on Nomenclature 

 and Classification of Sedimentary Formations, 1905). 



At the southern end of Lake Canandaigua, J. M. Clarke 

 discovered an Upper Devonian fauna, 550 feet above the 

 Genesee formation, that has come to be known as the 

 High Point fauna. On becoming aware of this fauna, 

 Williams saw that it was closely related to the Rockford 

 fauna of Iowa and widely different from that of the 

 Upper Devonian of New York, "in the midst of which it 

 lay. ' ' Further analysis of the fauna led to the discovery 

 "that the species peculiar to it apparently had their 

 ancestors in the Middle Devonian of Europe ' ' and not in 

 that of America. This study then led him into that of 

 the Tully limestone of New York, where he found much 

 of the Cuboides fauna of Europe and Asia. This fauna 

 begins abruptly above the Hamilton, "and from it 

 upward, all through the Upper Devonian, is a fauna 

 closely related in its species with the Upper Devonian" 

 of Europe, Asia, British America, Iowa, and Nevada. 

 We see here the pointing out of a world-wide faunal 

 migration (Scope of Paleontology, 1892). 



Williams also pointed out that the Hamilton fauna has 

 its closest affinities in the Lower Devonian faunas of 

 South America, a fact first demonstrated by Steinmann 

 and LTlrich. These migrations ceased with the Hamilton, 

 at the close of which time there was crustal elevation 



Am. Jour. Sci.— Fourth Series, Vol. XLVI, No. 275. — November, 1918. 

 32 



