41 
FRESHWATER MOLLUSCA FROM CENTRAL ONTARIO 
By F. C. Baker and A. R. Calm 1 
Illustration 
Plate II. Staynicola caiascopium kemjri var. nov., Helisoma antrosa royalensis, and 
H, campamdata canadensis 
Page 
51 
INTRODUCTION 
The present paper is based on a large collection of freshwater mollusca 
made by the junior author during the summers of 1928 and 1929 in that 
part of Ontario between the International Boundary and Albany river. 
The complete itinerary is given later in this paper. The freshwater fauna 
of the region once known as Keewatin has been made historic by the 
writings of J. F. Whiteaves, Robert Bell, and George Dawson. Though 
portions of the territory have been studied and written upon, only one 
author has essayed to cover the entire area in a consideration of its mol- 
luscan aquatic fauna, Dali (1905) in his “Alaska Mollusks.” Mozley has 
recently taken up the study of the Manitoba fauna, adding greatly to the 
number of species represented and bringing the nomenclature down to the 
present time. The important papers relating to this area are listed in the 
bibliography. 
The region of central and northern Ontario is one of great interest to 
the student of geographic and ecologic variation. With its almost endless 
series of lakes, connected for the most part by rivers and sloughs, it affords 
the widest opportunity for the action of the laws of organic evolution upon 
the aquatic inhabitants. And that these laws have been in operation is 
evidenced by the varieties and species peculiar to this region. 
Fifty species and races are represented in the collection, of which 
nineteen are new to the region, two of these representing apparently new 
varieties. This is the largest single collection reported upon from this 
area. There have been recorded from central and northern Ontario seventy 
species and varieties of freshwater mollusca; adding the nineteen species 
and races herein recorded for the first time from the area, there is a total 
of eighty -nine species and races known. About fifty-five additional species 
and races are known from Manitoba and adjacent territory, which should 
be found in Ontario, giving a grand total of one hundred and forty-four 
species and races of freshwater mollusca that should be found in central 
and western Ontario. 
’Contribution from the Museum of Natural History, University of Illinois, No. 57. Contribution from the 
Zoological Laboratory, University of Illinois, No. 381. 
