156 THE ROYAL SOCIETY OF CANADA 



The fauna as a whole is restricted in species. This is due to the 

 pond-like character of the whole lake, the lack of a sand mud bottom 

 most favourable to many molluscs, and lack of wave action to aerate 

 the water. However, as previously noted, the present fauna is more 

 diverse than that of the ancient marl fauna. ^ 



^Whittaker, E. J. The Relationship of the Fossil Marl Fauna of McKay 

 Lake, Ottawa, to the Present Molluscan Fauna of the Lake. Ottawa Naturalist, 

 Vol. XXXII, No. 1, p. 15. 



