290 Postelsia 
high. The region is shownin Plate XXIII. fig. 2. 
Plate XXV. fig. r. shows many stages in the devel- 
opment of tide pools. 
Many points along the coast show elevated 
portions of rock which are exposed only at 
low tide; on either side of these projections are 
depressions into which the tide runs. These 
indicate a tide-pool region so old that the bar- 
riers between pools have been worn away and 
only the rough rock is left. 
Pools in conglomerate are few in number 
and possess no striking characteristics. The 
rock east of ‘‘Baird’s Point”’ is flat and gently 
sloping, and is pitted with several hundred 
incipient tide-pools, very shallow, and generally 
eircular. Uhere are no boulders, amd) thepine 
forms are few. There were found only Clado- 
phora, sea anemones, small barnacles, and eel 
grass, a marked contrast to the variety found 
in the sandstone pools in this same region. 
As the pools are washed by the high tides and 
possess good illumination, it may be supposed 
that the paucity of, life forms is due) to seme 
youth of the pools. 
