LYMN^EIME OF NORTH AMERICA. 387 



sonian, Mackenzian, Nova Scotian and Upper Mississippian regions. 

 Additional records are needed from the Mackenzian and Hudsonian 

 regions, as well as from the northwestern part of the Upper Missis- 

 sippian region, where the species has been confused with binneyi and 

 apicina. In the United States (with the exception of the North Dakota 

 record) no authentic specimens have been personally examined from 

 west of the' 95° of longitude. 1 



EXTREME RECORDS. 1 



North Dakota: Riviere des Lacs, Ward Co. (Dawson). 



Keewatin : Oxford Lake; Great Playgreen Lake (Bell) ; Mistassin Lake, 

 Attawapiskat River; Kawinogans River; Winisk River; Ozhiski Lake (Mclnnes; 

 Whiteaves) ; Ekwan River; Knee Lake; Albany River and Trout Lake (Whit- 

 eaves ) . 



Mackenzie: Fort Resolution, Great Slave Lake (Kennicott). 



Manitoba: Dufferin, Provancher Dist. (Dawson); Lake Manitoba (Han- 

 ham); Lake Winnipeg (Kennicott). 



Ontario: Moose Factory, Moose River, Nipissing District (Drexler) ; 

 Fort William and north shore Lake Superior, Thunder Bay Dist. (Gould). 



Saskatchewan : Grand Rapids, Saskatchewan River, Lake Winnipeg, 

 (Smith. Inst.). 



Geological Distribution : (Figure 44). Pleistocene. The only- 

 records secured of the occurrence of this species in a fossil state have 

 been from New York. It will undoubtedly be found fossil throughout a 

 wide area when carefully searched for and correctly identified. 



RECORDS. 

 GRAVEL deposits. 

 New York : Gravel beds, Goat Island, Whirlpool and Foster's Flats, Niag- 

 ara River (Letson). 



INTERGLACIAL DRIFT. 



New York: Interglacial drift, Niagara Falls (A. Coleman). 



Ecology : Catascopium is plentiful in large bodies of water, such 

 as lakes, rivers and bays. It is especially abundant along the shore 

 of the Genesee River, in Rochester, N. Y. This habitat is of especial 

 interest in view of the fact that this river has been used for over ten 

 years as receptacle for the sewage of the city. Catascopium, how- 

 ever, seems to thrive in this water which now has the consistency of 

 dirty dish-water and is greasy to the touch. The effect of seven years 

 of life in this environment is plainly seen by comparing collections 



^Iissouri: Flat Creek, Pettis Co. (Sampson). 



Kansas: Erie, Neosho Co. (Call; Ferriss); Oswego; Labette Co. (Call; 

 Newton). 



These records, as well as Sampson's record in the Nautilus, VII, page 33, 

 are to be viewed with suspicion until verified by the examination of speci- 

 mens. No authentic material from as far south has been seen and it is quite 

 probable that the records were based on short-spired shells of palustris. No 

 mention of catascopium is made by Sampson in his report published in the 

 Arkansas Geological Survey. Special search should be made for this species 

 in this area. 



