* 

 18 The Ottawa Naturalist. [Mav 







general features of this locality in so far as they affect the character 

 of*the molluscan fauna. 



The Lake Simcoe district differs considerably from that of 

 Toronto in its flora and .fauna, which is of a more northern character, 

 due to its comparative remoteness from the modifying influence of 

 Lake Ontario and its somewhat greater elevation, Lake Simcoe being 

 about 475 feet above Lake Ontario. Whereas Toronto may be said to 

 be on the edge of the Carolinian or Upper Austral Zone, Lake Simcoe 

 is typical of the Alleghanian or Transition Zone. The shores of the 

 lake are almost everywhere low and flat and in the vicinity of De 

 Grassi Point are for the most part inclined to be more or less swampy. 

 The existence of the "Point* 1 is due to the presence of a somewhat 

 higher area of boulder clay forming an angular prominence, the shores 

 of which face north and east to southeast respectively. The clay 

 banks rise abruptly to a maximum height of about ten feet near the 

 apex of the prominence but gradually descend on either side to the 

 usual low level. 



The clay area is connected with the higher land farther from the 

 lake by a sand-covered ridge, which follows a southwesterly direction 

 roughly parallel to the lake shore for about three-quarters of a mile. 

 On the southeast side of the ridge there is a gentle slope to the lake 

 shore, while on the other side is an extensive area of low, densely 

 wooded land, bounded on the north by the north, shore of the "Point." 



The tree growth of De Grassi Point consists of a mixture of 

 deciduous and coniferous trees, presenting a considerable variety of 

 forest types within a very limited area. The clay area is largely, 

 covered by a fine grove of red oak, particularly along the shore where 

 the summer cottages are situated, while the characteristic trees of the 

 sandy ridge, are red oak, white pine and balsam fir, although many 

 other kinds are also present. 



The southeastern slope is partly occupied by pastures but there is 

 a considerable area of woodland, varying in character from a mixture 

 of coniferous and softer deciduous trees, which prevail on the lower 

 areas, particularly near the shore, to a typical hardwood forest on some 

 of the higher parts of the slope. The prevalent trees of the former 

 type are white cedar, balsam fir, aspen and balsam poplar, canoe-birch, 

 elm, black ash, white spruce, etc., while in the typical. hardwood areas 

 sugar maple, beech, basswood, yellow birch and hemlock are the 

 principal species, though many others occur. The extreme hardwood 

 forest type is represented by a small area, wooded almost entirely with 

 sugar maple and beech, with a scattering of other trees, such as butter- 

 nut and basswood and having a very rich soil, as indicated by the 

 larger size of many of the herbaceous plants, notably the red and white 

 trilliums and adder's-tongues and the presence of several species such 

 as the spring beauty and squirrel-corn, which do not occur elsewhere 



