CANADA 
DEPARTMENT OF MINES 
Hon. T. A. Crerar, Minister; Charles Camsell, Deputy Minister 
NATIONAL MUSEUM OF CANADA 
W. H. Collins, Acting Director 
BULLETIN No. 79 
Biological Series No. 21 
The Freshwater Mollusc Helisoma 
Corpulentum and Its Relatives 
in Canada 
BY 
F. C. Baker 
OTTAWA 
J. O. PATENAUDE, I.S.O. 
PRINTER TO THE KING'S MOST EXCELLENT MAJESTY 
1936 
Price, 25 cents 
