255 



being thinner, and in having the furrows between the plicae unusually 

 deep and sharp. The costse on the posterodorsal slope are very marked, 

 and the epidermis is jet black. The umbones are considerably eroded. 



Distribution of Mussels in the Lake. 



In rivers, where there is a great variety of conditions, such as dif- 

 ferences of current, bottom, etc., one finds the different species of mus- 

 sels inhabiting different localities and different situations. In the lakes, 

 where we have comparatively few species of mussels and not such im- 

 portant differences of environment, the distribution of the various 

 species is much the same. The same conditions, such as rather shallow 

 water and moderately firm bottom, are equally suitable for all. A few 

 important exceptions may be noted, as for example, the less common 

 species of the lakes are often more or less local in distribution. The 

 only well-marked bed of Qvadrula rubiginosa in the lakes is in the Lost 

 Lake mussel-bed below the Bardsley cottage, and this is the only place 

 where Lamjysilis subrostrata can be collected in any considerable num- 

 bers. Lcmipsilis glans has a marked preference for the shallow water 

 at the edge of the thoroughfare between the lakes; occasional examples 

 can, however, be picked up almost anywhere along the shore, and it 

 appears to be increasing considerably along shore at Long Point. Ano- 

 donta grandis footiana, which can live in softer bottom than the other 

 mussels, has a considerably wider distribution, and was dredged in 

 deeper water than any of the other mussels. 



The mussels are to be found almost anywhere in water from 2 to 5 

 or 6 feet deep where the bottom is more or less sandy or marly. The 

 beds are composed chiefly of the three principal species of the lake, 

 Lmnpsilis luteola, Unio gibbosus and Anodonta grandis footiana, with 

 the less common species sparsely interspersed. Especially good mussel 

 beds occur at Long Point, along shore by Farrar's and McDonald's, 

 along the depot grounds in Aubbenaubee Bay out from the Military 

 Academy, and in the shallow water just beyond the mouth of Norris 

 Inlet. Mussels are fairly well scattered from Long Point more or less 

 continuously all the way southward to beyond Overmyer's hill, and from 

 a little north of the ice-houses all the way around to the Military 

 Academy. They are quite abundant in the neighborhood of Winfield's 



