MUSSEL FAUNA OF MAUMEE EIVER. 15 



there were many exuviae on the water surface and on objects along 

 shore. Many of the insects died shortly after emerging. 



On the first visit to the swimming-hole, the afternoon of June 14, 

 a large number of johnny darters {Boleosoma nigrum) and a few 

 minnows were observed dead along shore. All the fishes were quite 

 small, apparently the young of the year. It is very likely that some 

 sudden pollution of the river about that time was the cause of the 

 death of the fishes as well as that of a great number of large craw-' 

 fishes on shore and mussels in the water. Some time during the sum- 

 mer it was reported that dyestuff had been poured from the knitting 

 mills some distance above into the river and had caused a Avholesale 

 destruction of fishes, which died in such numbers as to render por- 

 tions of the city along the river scarcely habitable. In addition to 

 the dead fishes mentioned above, the following species were observed : 

 Catfishes (young, probably Ameiurus natalis), mad toms {Schil- 

 beodes gyfinus), golden shiners {Ahramis crysoleucas), carp {Cypri- 

 nus carpio), and sunfishes {Eupomotis gihhosus). In the previous 

 year a number of small black suckers {Catostomus nigricans) were 

 seen at this place. 



Of reptiles, a few painted turtles {Chry semis marginata) were 

 found. There were no indications of aquatic mammals, such as 

 tracks or piles of shells along the shore. Late in autumn, however, 

 a good many crawfishes Avere seen along shore with backs bitten 

 open, and this may have been done by a muskrat or a mink. 



As has been said, although a few mussels could be found above 

 the main bed, the greater number were to be obtained just at the 

 head of the riffles in a fairly compact bed. The mussel bed itself is 

 quite small, probably not more than 2,000 square feet in extent, and 

 commercial operations would clean it out in a very short time. On 

 several occasions the water was clear enough to see the bottom and 

 the distribution of the mussels fairly well. The mussels did not 

 appear to be moving. They were headed mostly downstream, the 

 natural position for feeding mussels, and were not deeply buried; 

 about half of the shell projected out of the mud. The projecting 

 portion was more or less stained and frequently covered with an algal 

 growth. 



On June 20 this bed was gone over with considerable thorough- 

 ness and a number of mussels collected. These were placed on shore, 

 counted, and sorted over, and, after a number of representative 

 shells such as were desired for specimens were picked out, the rest 

 were thrown back. All the shells, especially L. rectus and Z. liga- 

 mentinus^ were large and fine. A num})er of the living animals were 

 measured and weighed, with the results shown on the next page. 



