126 



The Canadian Field-Naturalist 



[Vol. XXXIV. 



Insects. general below tide water. 



MOSQUITOES. Not very numerous along rivers, MOURNING CLOAK BUTTERFLY, Aglais antiopa L. 



except at mouth of Missinaibi. Very plentiful at Two seen near foot of Long Rapids, Mattagami 



Moose Factory, on August 18th and 19th, and in river, August 13th. 



THE LARGER FRESHWATER CRUSTACEA OF CANADA AND ALASKA. 



By Frits Johansen. 



Introduction. 

 Though the freshwater-crustacea are of great im- 

 portance as food for fishes, birds, water-insects, etc., 

 occuring in vast numbers even in ponds, and cer- 

 tain of them (Malacostraca) are conspicuous enough 

 by their size, their occurrence in Canada and Alas- 

 ka has been little studied, apart from cray-fishes. 

 A. G. Huntsman has already called attention to this 

 fact in his "Freshwater-Malacostraca of Ontario," 

 (Contributions to Canadian Biology 1911-14, Fasc. 

 II, p. 145), and he also there emphasizes how com- 

 paratively little is known about their habits and 

 life-histories, on which their distribution in and their 

 introduction into the innumerable ponds, creeks and 

 lakes in Canada depends. 



So far as Alaska is concerned cray-fishes are not 

 found there (they may occur in southern Alaska), 

 and the other freshwater-crustacea do not seem to 

 have appealed much to the many collectors in that 

 territory as of sufficient interest, even to the extent 

 of their picking up a few odd specimens, so easily 

 secured by pulling up water plants, by using a 

 catcher from the margin of a lake or pond, or by 

 examining stomachs of fishes caught. The writer 

 has had personal experience of how common fresh- 

 water-crustacea are along the arctic coast of Alas- 

 ka, and it IS to be hoped that future collectors will 

 connect up the collections made here with the data 

 secured in the western provinces of Canada, by an 

 examination of the bodies of freshwater in the more 

 southern parts of Alaska and of Yukon Territory, 

 so easily accessible all the year round.* As is the 

 case for the United States so also for Canada the 

 hitherto published records of freshwater-crustacea 

 refer mainly to the Great Lakes and their ramifica- 

 tions and tributaries. The present writer has only 

 a few new data or collections to record from this 

 area, and has only a tourist's acquaintance with these 

 extensive bodies of water. The present article 

 therefore does not claim to treat the basin of the 

 Great Lakes exhaustively; other writers are more 

 qualified to do so, and as mentioned, these bodies of 



*See recent collections recorcled by Pear.se (1913). 



freshwater have been studied fairly well before (see 

 bibliography), even Georgian Bay and other pure- 

 ly Canadian (Ontario) localities (Huntsman). 



But, thanks to the efforts of various Canadian 

 expeditions and collectors quite a few freshwater- 

 crustacea have been collected in Canada and the 

 arctic part of Alaska, in various ponds, lakes and 

 streams, particularly in more recent years. I have 

 gone over most of the larger forms from the col- 

 lections (Amphipods, Isopods, Phyllopcds), except 

 cray-fishes, in the possession of the various museums 

 in Canada; and by letters and words I have tried 

 to stimulate the securing of further data, in par- 

 ticular from hitherto quite unrepresented areas. The 

 result has been most gratifying and the time seems 

 now opportune to publish these many data, which 

 perhaps will create a still greater interest in the 

 subject. I may add that the freshwater-crustacea 

 (Amphipcda, Phyllopoda, Cladocera, Copepoda, 

 Ostracoda) I secured along the arctic coast of 

 America while with the southern party of the Can- 

 adian Arctic Expedition, 1913-16, are treated in 

 detail by various specialists in Volume VII, of the 

 scientific reports of the said expedition (Ottawa, 

 1920), so I need only here refer to these reports. 



To give an idea of the many widely separated 

 localities in Canada and Alaska from which we 

 (mainly the Victoria Memorial Museum, Ottawa) 

 have specimens of freshwater-crustacea I mention 

 the following places: Teller (Port Clarence); 

 Point Barrow, Camden Bay, Demarcation Point 

 and Herschel Island, along the north coast of Alas- 

 ka and Yukon Territory; International Boundary 

 line between New Rampart House and Arctic 

 coast ; Cape Bathurst and various places on the 

 south side of Dolphin and Union Strait in Arctic 

 Canada; Fullerton on the west side of Hudson 

 Bay; east coast of Grinnell land; Labrador coast 

 and Newfoundland; western, northern and eastern 

 coasts of Greenland (collections in Copenhagen) ; 

 west side of Cape Breton island, N.S. ; Nova 

 Scotia, (according to Dr. Marsh's and Juday's let- 

 ters to me of March 10, II, 1920); Magdalen 

 islands, Tadousac and Quebec City, P. Que. ; 



