

THE OTTAWA NATURALIST 



Vol. XXXI. MAY, 1917. No. 2. 



NOTES ON THE LAND MOLLUSCA OF DE GRASSI POINT, 

 LAKE SIMCOE, AND OTHER ONTARIO LOCALITIES. 



By E. M. Walker, F.R.S.C, University of Toronto. 



When the Royal Ontario Museum of Zoology was opened in the 

 spring of 1914 it was our first aim to assemble such material as was 

 available for the formation of a collection illustrating the Canadian 

 fauna. One of the groups in which this material was found to be 

 conspicuously lacking was the land Mollusca and to supply this 

 deficiency the writer decided to spend a part of the summer of 1915 

 in making the nucleus of a collection of our local species of land snails 

 and slugs. 



I am not a malacologist and I am well aware that in collecting in 

 an unfamiliar field one is sure to overlook many species, if the collect- 

 ing is done without some previous knowledge of the fauna and of the 

 habitats of its various members. I therefore endeavoured to familiar- 

 ize myself with the subject as far as circumstances would permit and 

 made an effort to determine each species as soon as possible after it 

 was collected. Had this not been done there is no doubt that many of 

 the more minute forms would have been overlooked. 



The season of 1915 was unusually cool and wet and thus proved 

 to be a very favourable one for land Mollusca. Most of the summer 

 was spent at De Grassi Point, on the west shore of Cooke's Bay, Lake 

 Simcoe, about three and one-half miles from the upper or southern end 

 of the lake. A few days were also spent at Go Home Bay (Bushby 

 Inlet), on the east shore of Georgian Bay, and some collecting was also 

 done in the vicinity of Toronto and at Port Rowan and St. William's, 

 near Long Point, Lake Erie. During the season of 1916 a number of 

 species were collected by Miss Norma H. C. Ford in the vicinity of 

 Toronto and she has kindly permitted me to include her records with 

 my own. 



As the greater portion of the collection was made at De Grassi 

 Point and is believed to contain a nearly complete representation of the 

 species found there it may be worth while to describe briefly the 



