Skinner : tide pool vegetation of port Renfrew. 149 



ii. Cheilosporum planiusculum. 



Occurs near the bottom of the pool on the north. 



Pool No. IV. 



Location. — Mid-tide pool. At a level three feet below No. 

 3. Distant from the edge of the ridge twelve feet. 



Exposure to Tide. — The pool is filled repeatedly at mid tide. 

 An occasional wave enters from the southwest but in general 

 the pool is filled from the east end by the surf thrown up as a 

 wave is broken violently on the ledge to the east. 



The drainage is to the south and southwest. The west end 

 of the pool is left usually in comparative quiet. 



Shape and Dimensions. — Diameter east and west eleven feet. 

 Diameter north and south six and one half feet. Depth six and 

 one half feet. 



In general the edge of the pool overhangs slightly. Sides 

 quite smooth and regular, occasionally broken with crevices 

 and holes. Below the overhanging rim the sides on the north 

 and south slope gradually to the bottom. The east side recedes 

 uniformly. On the west, about one foot below the surface, a 

 shelf of rocks projects. Below this shelf the side slopes gradu- 

 ally to the bottom. 



Bottom quite regular. Covered with rocks of various size. 



Flora : Kind and Distribution. 



1. Corallina vancouveriensis. 



Occurs around the rim of the pool on the north and west, 

 extends down four feet. 



2. Rhodomela larix sp. with Sor anther a ulvoides. 

 Occupies a zone about one foot wide three feet below the 



surface. 



3. Phyllospadix scouleri. 



Occurs on the northwest, west, and southwest. On the north- 

 west it extends nearly to the bottom. 



4. Cheilosporum calif ornicum. 



Occurs three feet below the surface on the east and south 

 beneath No. 2. 



5. Cheilosporum frondescens. 



Occurs about four feet below the surface on the south and 

 north. Seemingly protected by Nos. 5 and 3. 



