MUSSELS OF CENTRAL AND NORTHERN MINNESOTA. 11 



the others and perhaps even better, but are not sufficient in quantity 

 to warrant shipping them for any distance. Such factories deserve 

 the encouragement of both fishermen and manufacturers. 



MUSSELS OF THE MINNESOTA RIVER GROUP. 



As has been already stated, the Minnesota River and its tributaries 

 have been pretty thoroughly worked up by representatives of the 

 button factories. Like the St. Croix, this river empties into the 

 Mississippi below the Falls of St. Anthony, and so affords a free 

 passage for all kinds of fish and mussels. Furthermore, it formed a 

 part of the glacial River Warren, which was the outlet of Lake Agassiz, 

 and thus there has been no break in its connection with the 

 Mississippi. 



The present investigation did not include the river itself, but only 

 some of the lakes in Douglas County that eventually drain into it by 

 way of the Chippewa River. 



•Within a radius of 6 miles from Alexandria, the county seat of 

 Douglas County, there are 20 small lakes, several of which have 

 become quite noted summer resorts. 



Lakes Agnes, Henry, and Winona are close to the railroad station, 

 small, shallow, and filled with water plants. The only mussels found 

 in them were dwarfed and thin-shelled nmckets {L. luteola), whose 

 epidermis was highly polished and somewhat marly and whjQse 

 nacre was a beautiful smoky brown. 



Four miles north of the city there is a group of three larger 

 and much deeper lakes, called, respectively, Darling, Carlos, and 

 L' Homme Dieu. These lakes are comparatively free from water 

 weeds, have sand and gravel bottoms, are very deep, and contain 

 plenty of fish, but the only mussels that could be found in them 

 were Anodontoides freussacianus modestus and Anodonta pejpiniana, 



A similar fauna was reported for the other 14 lakes, so that it does 

 not appear as if any of the lakes in Douglas County contained comr 

 mercial shells. Nor do any of them present conditions that would 

 recommend the introduction of merchantable species by means of 

 artificial propagation. 



Some of the isolated lakes in this drainage, however, present 

 entirely different conditions. 



MUSSELS OF THE RED RIVER GROUP. 



The lakes and rivers belonging to this group were populated with 

 mussels from the Mississippi River by way of the glacial river Warren 

 and Lake Agassiz. Since the disappearance of this glacial river and 

 lake the Minnesota River drainage and the Red River drainage have 

 been separated, and each has acquired peculiarities of its own. 

 The Red River turns northward along the western border of the 



