ee COMPOSITION, ORIGIN, AND: RELATIONSEMES 
OFIOEE -CORNIPEROUS FAUNA, IN- THE APRA 
LACHIAN PROVINCE OF NORTH AMERICA. 
THE Devonian was pre-eminently a period of provincial 
development of marine faunas. In the Appalachian Province 
of North America, lying to the west of the ancient Appalachian 
land and to the east of the Wisconsin-Ozark land, there were 
introduced successively, with little or no foreshadowing, the 
Helderbergian, Oriskany, Corniferous, Hamilton, and Upper 
Devonian faunas. Each of these faunas possesses characteristics 
peculiar to itself which could not have been derived from the 
next preceding fauna, but which must have been in process of 
evolution during a Jong period of time in some other region of 
the earth. It is perhaps not too much to assume that each of 
these faunas had its ultimate origin from the earlier, more cos- 
mopolitan fauna of Silurian time, and that their evolutions were 
in progress contemporaneously, each in its own more or less 
isolated province. Their succession, therefore, in the Appa- 
lachian Province may be entirely accidental rather than genetic. 
The amount of faunal change initiated with the introduction 
of these various faunas differs greatly in degree. In the case 
of the Hamilton fauna, there are a large number of species which 
are common also to the preceding Corniferous fauna; in fact, 
the great majority of the members of the Hamilton fauna are a 
residuum or an evolution product from the Corniferous fauna. 
The number of strange forms’ introduced is small, but they are 
of such a nature as to show the presence at this time of a means 
of communication between the Appalachian province and a 
southern hemisphere province, probably in South America. 
The presence of these forms, with the internal changes which 
tThe chief of these exotic Hamilton species are 7vopidoleptus carinatus Con., 
Vitulina pustulosa H., and Chonetes coronatus Con. 
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