6 MtfSSEL FAUNA OF MAUMEE EI\T3!l. 



to the east of the Tiffin and Auglaize Rivers, The former drainage 

 of the St. Joseph and St. Marys Rivers through the Wabash is in- 

 dicated by the peculiar turn they make at Fort Wayne, where they 

 unite to form the Maumee. This sudden change, of course, is so 

 striking a feature that it has excited comment by almost everyone 

 who has considered the topography of the region. The situation is 

 well expressed by Mr. Simpson who says: 



The St. Josephs. St. Marys, and Auglaize Rivers, tributaries of the Maumee, 

 flow in the direction of the Wabash ; the two former join at Fort Wayne and 

 flow partly backward as the Maumee, the whole looking like a tree with its 

 branches broken down and hanging against its trunk.° 



From the time of the closing up of the Wabash outlet until the 

 St. Lawrence was reopened, the only outlet for Lake Maumee was 

 through the Huronian channel into Lake Chicago, and thence into 

 the Des Plaines and Illinois Rivers. All the mussels, therefore, 

 which took part in restocking Lake Maumee during this period 

 belonged to the Illinois River fauna and entered the lake by this 

 roundabout channel. The Unionidse are essentially inhabitants of 

 shallow water and would have spread along the margin of these 

 glacial lakes. As the level of the lakes was gradually lowered and 

 the present system of drainage was established, the mussels naturally 

 followed the retreating waters, and thus finally found their way into 

 the river beds where they now live. 



This account of the origin of the present mussel fauna in the 

 Maumee and upper Wabash Basins is adapted from several geologi- 

 cal reports of the States of Indiana and Michigan and from an 

 excellent paper on the " Distribution of the Unionidse in Michigan " 

 by Bryant Walker.'' 



From the foregoing account of the manner in which the stock- 

 ing of the Maumee Basin took place, it would naturally be inferred 

 that in the lists of species of mussels obtained at the various stations 

 on the Maumee and Wabash Rivers by the party, there should be 

 more than the usual amount of similarity between those from the 

 headwaters of the two rivers, and this similarity should decrease the 

 farther down the respective rivers the comparison is made. Such 

 we find to be actually the case. (See p. 38.) 



But there is another factor which may at least claim a share of 

 the credit for the correspondence in species. 



The Wabash and Erie Canal was in active operation between 

 these two rivers for nearly half of the last century. Starting at 

 Toledo, Ohio, it ran along the bank of the Maumee for the entire 

 length of that river to Fort Wayne. There it crossed the narrow 

 strip of country between the headwaters of the two rivers, ran along 



• American Naturalist, loc. cit. 



"Author's separate of a paper read before the Michigan Academy of Science, March, 



