140 THE NAUTILUS. 



where. The sawdust and other waste is thrown in the water, and 

 is forming extensive deposits in the river and tributaries. It is very 

 destructive to Molluscan and other animal life. 



Anodonta marginata Say. Is distributed in the main river and 

 the lakes and tributaries on muddy bottom. Common. 



Alasmidonta undulata Say. St. John's River at Fort Kent and 

 Conners. Also in the Aroostook and Fish Rivers. Rare. 



Margaritana margaritifera Linne. Is found in the Aroostook 

 River and some of its tributaries. I have not seen M. margaritifera 

 in any of the St. John's River tributaries above Grand Falls. If it 

 is living in the upper part of St. John's River it is rare. 



Unio complanatus Solander. Generally distributed in the Aroos- 

 took and Fish Rivers, rare in the St. John's River. In Temiscouata 

 Lake is a small form of this species that is common in deep water in 

 the lakes of Maine (Fish River lakes). 



Sphaesrium striatinum Lamarck. Common on rocky bottom in 

 Fish River, in St. John's River at Fort Kent, and in Madawaska 

 River at St. Rose. 



Ancylus borealis Morse. In 1899 I found five specimens of this 

 rare shell in the St. John's River at Fort Kent. 



Lymncea (Galba} emarginata Say. Second Eagle Lake, Fish 

 River and St. John's River at Fort Kent, abundant on rock bottom 

 feeding on Conferva. 



Lymncea ( Galba~) emarginata mighelsi Binney. This variety is 

 represented by fine large specimens at Square, Cross, and Portage 

 Lakes. The type of Lymncga ampla Mighels came from Square 

 Lake. 



Lymnaa ( Galbd) emarginata canadensis Sowerby. A large col- 

 ony was found on rocky bottom on the north side of Mt. Wissic, 

 Temiscouata Lake, Province of Quebec. The colony is located in a 

 partly sheltered cove in water two to ten feet deep or more. Among 

 those found here I have noted certain peculiarities that are common 

 to all species that are found on rocky bottom in more or less shel- 

 tered position. Each colony has its peculiar variations and need a 

 geographical name to express their habitat rather than a specific 

 designation of any individual. See F. C. Baker's work on " The 

 LymnaBidas of North and Middle America." 



Physa heterostropha Say. Common in the St. John's River at 

 Fort Kent, also in the Fish and Aroostook Rivers. 



