410 C. R. Stauffer — The Minnesota Devonian. 



western Devonian f annas bnt there are still others equally 

 suggestive. Of those common to the Iowa Devonian half 

 are general Hamilton forms while most of the others 

 belong in the fanna of the Lime Creek shales and are 

 hardly to be considered the most characteristic Iowa 

 Devonian fossils. And at any rate the Lime Creek fauna 

 is quite different from the Cedar Valley fauna and decid- 

 edly a later development as far as North America is con- 

 cerned. The String ocephalus zone of Manitoba carries 

 about 20% Onondaga forms but less than 5% Cedar Val- 

 ley species. The later Devonian faunas of the northwest 

 are also decidedly different from that of the Cedar Valley 

 and appear to have even less in common with it. In 

 short, so remote is the relationship between the fauna of 

 the Minnesota Devonian and that known from Manitoba 

 and the Mackenzie valley that the idea of a direct sea con- 

 nection between these two regions, during the deposition 

 of the Cedar Valley limestone, should be abandoned. 

 Unless the studies at present being pursued in Canada by 

 Dr. Kindle, in Iowa by Professor Thomas, and in Mis- 

 souri by Dr. Branson, should show a closer relationship 

 for the upper beds than is indicated by our present knowl- 

 edge it is probable that the supposed sea connection 

 across Minnesota during Upper Devonian should also be 

 abandoned. 



The buried granite ridge, which crosses central Kan- 

 sas (12) in a north-northeast direction, was land during 

 Devonian time and probably an extension of the land 

 area of the Lake Superior region. In fact the pre-Cam- 

 brian of this latter region crosses Minnesota as a buried 

 ridge and disappears, under the Sioux quartzite, near the 

 southwestern corner of the state. While the sea evi- 

 dently crossed part of this old mountain range during cer- 

 tain periods such as the Upper Cambrian and the late Cre- 

 taceous, there are no definite indications that any part of 

 it was submerged during the Devonian and the lack of the 

 expected relationship between the Devonian faunas on 

 either side of the ridge seems to indicate that there was 

 a land barrier in that region during the life of these 

 faunas. 



The Devonian is represented by 8000 feet of limestone 

 and shale in the Great Basin. Its fauna is only partially 

 known but "Walcott (13) found it to be a large and varied 



