92 The Fauna of the Magnesian Series. 



Then, too, a study of the plants introduced through the 

 agency of the railroad would be of interest. But in a section 

 so near to the original in nature a notice of the abundance 

 of peculiar Saprophytic plants must be taken. Everywhere 

 in the different timbered localities, in the swamps and over 

 the burnt woodlands Agaricinae and other fleshy fungi were 

 especially noticeable. 



The flora of the *' Thousand lakes " must also be noted, 

 and it is well to notice that even in the counties most thickly 

 studded with lakes, each has its characteristic alga. 



November 13, 1892. 



[Paper F.] 

 THE FAUNA OF THE MAGNESIAN SERIES. 



DESCRIPTIONS OF FOSSILS. 



F. W. Sardeson* 



The object in presenting the folio wing notes on the faunal 

 characters of the Magnesian series is to establish a system- 

 atic table as a basis for the rational division of the forma- 

 tions of the series. A mere compilation of species already 

 described and referred to this series would seem to prove the 

 existence of two faunas, one for the ** Lower Magnesian*' 

 and another for the '^ Potsdam" or *' Lower Sandstone" of 

 the Upper Mississippi basin. But no such two faunas exist. 

 Each is a confusion of different faunas. There were also very 

 few species known and these of very rare occurrence. In 

 searching for these old species— for all data had to be veri- 

 fied — several new species have been discovered. 



All fossils collected have been referred with the greatest 

 care to their proper division of the '* Lower Magnesian " 

 (Owen), viz.: 



1. Shakopee dolomite. 



2. New Richmond sandstone. 



3. Oneota dolomite. 



• Partially revised November 18, 1895. 



