396 Canadian Record of Science 



Spirogyra but only one Zygnema was found in a fruit- 

 ing condition. 



(2) Amherst Park: 



This is a section of land at the north-east of the 

 mountain, which is now beginning to be built up. There 

 is a thin layer of sandy soil over the surface of the 

 Trenton limestone, which is well developed here. This 

 has been and is still being extensively quarried. Many 

 abandoned workings exist, which have nearly all be- 

 come filled with water, forming ponds of some size and 

 great depth. The limestone is cut at intervals by dykes 

 from the fourth period of Mount Royal's activity, and 

 these, not having the commercial value of the limestone, 

 have been left intact and serve to divide some of the 

 quarries into ponds. 



In two of the largest quarries, Anabena inequalis, 

 (Kiitz) Born. & Flah., was found covering the whole 

 surface like a thin creamy -yellow film. Associated with 

 this was a very little Oscillatorio. Very few water weeds 

 were to be seen in any of these artificial ponds, save 

 here and there a few tufts of Elodea, probably because 

 the sides were too steep and sheer to afford any con- 

 venient place for it to take root. It was noticeable that 

 each quarry invariably had a dominant form. The 

 shallower pools contained the filamentous forms, some 

 presenting a very beautiful appearance because of the 

 long graceful strands of filaments which streamed up 

 from the bottom. These pools were supplied with water 

 both by drainage from the surrounding plain and from 

 tiny springs. 



This was by far the richest region discovered, both 

 in the number of species and also in the quantity of 

 individuals. More than twenty of these ponds, large and 

 small, were visited upon several occasions and a great 

 deal of material was collected. The ponds which contained 

 the most refuse — these abandoned quarries are evi- 



