MUSSEL FAUNA OF MAUMEE RIVER. 



9 



Kirsch's report and the present one may be regarded as supplemen- 

 tary to each other. 



The following general observations were made concerning the 

 biology of the stream : 



Among the aquatic plants, Oscillatoria was abundant in the St. 

 Marys Eiver and the upper portion of the Maumee down as far as 

 Kern Eeservation, 7 miles below Fort Wayne. In the St. Marys 

 this plant was found floating in large blackish or blue-green bunches 

 on the surface of the river ; ^ farther down much of the floating Oscil- 

 latoria seemed recently washed in. Filamentous algse, probably 

 Cladophora^ grew on the rocks in the bottom and occasionally on 

 the shells of the mussels. Wild celery (Vallisneria spiralis) was 

 abundant on the bottom of the St. Marys at Fort Wayne, but was 

 not conspicuous farther down. The dense-flowered water willow 

 {Dianthera americana) fringed the edges of the river and lower 

 portions of the canal all along the way and was one of the plants 

 most constantly seen. During the latter part of the cruise along the 

 Miami and Erie Canal this plant was covered with large tangled 

 clumps of dodder, so that the prospect either way along the canal 

 was lined with great masses of yellow here and there. Algse of 

 many sorts grew in great abundance in the Maumee below the dam 

 at Defiance. Portions of the canal from Napoleon, Ohio, to the locks 

 below were covered with a dense scum of delicate little water fern, 

 AzoUa caroliniama. Along the lower stretches of the canal Cera- 

 tophyllum was abundant in stretches of quiet water. Typha latifolia^ 

 the narrow-leaved cat-tail, formed a dense hedgelike grow^th along the 

 edge of the canal in places. The spatterdock, Nymphcea advena^ was 

 fairly common along the lower reaches of the canal and the white 

 water lily, Castalia odorata^ occasional. Duckweeds were common 

 in the canal, but not noted in the river. 



As to animal life, various species of protozoa were very abundant 

 in one place in the St. Marys, as will be described later on. (See 

 p. 13.) They were not noted farther down the river; however, there 

 was little opportunity to examine carefully for them. No plankton 

 was taken, but the material examined from the stomachs of mussels 

 probably gives a fair notion of the nature of the smaller free plank- 

 ton elements. Sponges and flatworms were rather common on rocks 

 and shells the whole length of the river. In addition to the mussels, 

 various mollusks such as Pleurocera^ Aneyliis, and Sphcerium> were 

 common. Crawfishes were abundant everywhere in the river, but were 

 not often noted in the canals. Aquatic insects and larvae were not 



" Further observations show that the presence of Oscillatoria and other minute organ- 

 isms is a periodic phenomenon. They accumulate during periods of low, stagnant water 

 but altogether disappear during periods of high water with rapid current. 



