5 GEORGE V. SESSIONAL PAPER No. 39b A. 1915 



VI. 



THE FRESH- WATER MALACOSTRACA OF ONTARIO. 



By A. G. Huntsman, B.A., M.B. , University of Toronto. 



{13 figures in the text) 



The greater part of the material upon which this paper is based was collected 

 at the Georgian Bay Biological Station. As it seemed desirable to bring together 

 records of all the species known to occur in the region of the Great Lakes, the 

 scope of the paper was extended beyond the Georgian Bay region and material from 

 other localities in Ontario was studied. 



The scope of the paper may be considered as the Canadian part of the region 

 of thQ Great Lakes, which is practically limited to the Province of Ontario. Only 

 a small part of our waters has as yet been examined, and the following list of 

 species cannot be considered as exhaustive, but it may be noted that few species 

 have been added to the list of Malacostraca reported from the Great Lakes in 

 "The Fresh-water Crustacea of the United States" published by S. I. Smith in 1874, 

 and probably very few remain to be added. 



As the literature necessary for the identification of species is more or less 

 scattered and inaccessible, it has been deemed advisable to include keys for the 

 determination of the species, together with figures of the principal parts useful 

 in diagnosis so that this account may serve as a basis for future work. 



Much work remains to be done to determine the distribution of the various 

 species. The localities from which specimens have been obtained, are given, 

 but no systematic collecting has been done in any part of the Province with the 

 exception of Georgian Bay. Doubtless the majority of the species occur through- 

 out the entire region, wherever suitable habitats are to be found. 



The importance of the Malacostraca in connection with our fresh-water fisher- 

 ies can scarcely be overestimated. They form the chief element in the food of 

 many of our food-fishes. Their large numbers, their free-living habits and their 

 general edibility render them particularly suitable as fish food. It is very de- 

 sirable to learn more of their life-histories, habits, food, etc., so that their numbers 

 may be increased or extralimital species that are desirable may be introduced. 

 The practical value of such work would be very great, as the lake area of the 

 Dominion is exceedingly large and able to support an immense number of fish. 

 The probability of a successful issue of such researches is greater in the case of 

 fresh-water than in that of marine forms, owing to the fact that the various con- 

 ditions can be much more readily controlled in closed-in bodies of water. 



