Ulrich—Paleozoic Systems in Wisconsin. 
107 
limy deposits that must, on the basis of thickness alone, rank the 
Ozarkian among the most important of the Paleozoic systems. 
In North America the Ozarkian system has as good or a better 
foundation in its diastrophic history, volume and character of de¬ 
posits, and in its distinctive faunas than have the Silurian, De¬ 
vonian, Permian, Triassic, and Jurassic systems, most of which are 
generally accepted by stratigraphers. 
In the matter of areal distribution also, especially when we con¬ 
sider the fact that as one of the oldest of the Paleozoic systems its 
rocks are likely to be largely buried beneath younger sediments, 
the Ozarkian compares favorably with other Paleozoic systems. 
Kocks of its age are now definitely recognized as outcropping in 
New York, Vermont, New Jersey, Pennsylvania, Maryland, Vir¬ 
ginia, Tennessee, Georgia, Alabama, Missouri, Iowa, Wisconsin, 
Minnesota, Oklahoma, central and western Texas, Colorado, Idaho, 
Nevada, and, through the explorations of Walcott, in British Co¬ 
lumbia. By means of deep wells this already very widely demon¬ 
strated areal distribution doubtelss will be extended to other 
States. Moreover, there are good reasons for believing that the 
system is represented also in Quebec and Newfoundland and on the 
nther side of the Atlantic by the Tremadoc in Great Britain and 
perhaps in other European countries. For the present, however, 
certain very real difficulties, which always are encountered in the 
endeavor to correlate fossil shore and bottom faunas of widely sepa¬ 
rated provinces, forbid more definite statements regarding the possi¬ 
ble and probable representatives of the Ozarkian on other than the 
North American continent. 
