12 Postelsia 
2. River bed formation. 
a Banks and channel. 
b Rivers and streamlets. 
3. Lake beach formatione 
a Front beach. 
b Mid beach. 
C Back beach: 
4. Lake formation 
I. Marine formations. 
Vegetation of the tidal area. 
tr. Algal formation. 
Marine vegetation, as built up along the 
shores of Vancouver Island, falls into two gen- 
eral categories as indicated in the above synopsis. 
Since it is not the province of this essay to deal 
with the former of these two, it will merely be 
alluded to in passing. 
It is well known that this part of the west 
coast of North America shows an unusual de- 
velopment of forms belonging to the Rhodophy- 
ceae and especially the Phaeophyceae. Some of 
the larger kelps like Nereocystis, Laminaria, 
Alaria, Egregia, Lessonia, Pterygophora, etc., not 
only attain here great proportions but also occur 
