32 MUSSEL FAUNA OF MAUMEE EIVER. 



canal the town of Independence was located here at the dam, but 

 when the railroad superseded the canal the toAvn moved elsewhere. 

 The water above the dam backs for 7 miles up the Maumee and about 

 2 miles up the Tiffin and Auglaize Rivers and forms a charming 

 lakelike body of water below Defiance. This water is navigable 

 for small boats and launches, of which there were a considerable 

 number. The river is some 600 feet wide at the dam, and at the 

 time of our visit a thin sheet of water was pouring over. We had 

 been informed while at Defiance that there were many fine mussels 

 below the dam. (See fig. 4, pi. ii.) 



Examination of the place proved the accuracy of our informant 

 and showed that this locality was the richest collecting ground and 

 supported a greater variety and abundance of life than any other 

 stretch of the river. The river bed below the dam is a broad valley 

 with a limestone bottom, the river being broken up into a great num- 

 ber of pools and channels dotted with little islands overgrown with 

 willows. The water, sparkling and fresh after its rare over the 

 dam, seemed to make conditions exceptionally favorable for all sorts 

 of aquatic life. The shores of the pools were edged with water wil- 

 lows, and the stones on the bottom were covered with a rich growth 

 of algae of various species and hues, some growing in long ropy 

 masses; there were especially large clumps of Cladophora^ lending 

 a green color to the bottom, and numerous larvae of caddis and stone- 

 flies gluing the pebbles together. Many crawfishes were seen, and 

 Bryozoa were common on the rocks. There were many anglers in 

 high boots wading about in the racing currents. Flocks of black tern 

 were flying overhead, the first we had seen. 



Fringing the edges of the pools and islands were many rather small 

 shells, chiefly Plagiola elegans and young Quadrula lachrymosa that 

 had apparently been killed by fishermen for bait. By feeling about 

 in the sand in the shallow water shells could be found in great num- 

 bers, and they were of fine quality and very large size. The L. ven- 

 tncosus were the largest we had seen. Everything considered, these 

 are the most important mussel beds in the river, and this is one of the 

 places worthy of future study. 



It was at this place we found a couple of pearls, which, on account 

 of their minute size, were of no market value. They were, however, 

 of considerable interest, as, on account of their position, they served 

 to intensify the suspicion already entertained that pearl formation 

 may be excited by the presence of the marginal cyst. We are of the 

 opinion that this is an exceptionally favorable location for the carry- 

 ing on of investigations along this line. 



At the Defiance Dam we entered by means of a lock into the first 

 stretch of the canal, which runs from Defiance to Grand Rapids, Ohio. 



