DISTRIBUTION OF ALG 31 
The laminarian zone extends from low-water mark to the depth 
of fifteen fathoms. The Laminariacee and the beautiful red alge 
(Floridece) grow here. 
The third or coralline zone extends to the depth of about fifty 
fathoms. The alge of this zone, the nullipores, are incrusted 
with a deposit of lime which gives them the appearance of corals ; 
and, singularly enough, the corals, which are animal forms, 
simulate plant life. 
Again, algze have special habits and demand certain climates 
and seasons for their growth. Algologists register the place 
where a specimen is found, and in this way localities have been 
pretty well determined. However, great exactness has not been 
reached, and the collector is ever watchful to find an alga in 
some undiscovered home within the given range. Although 
alge grow from extreme high-water mark to the depth of fifty 
fathoms, almost every variety may be found on the beach, those 
growing in deep water being frequently torn off and washed 
ashore by the waves. The heaps of sea-wrack will often reward 
one who examines them carefully for deep-water species. Sea- 
weeds are most abundant on rocky shores, particularly where 
there are stratified rocks with crevices, which afford shelter from 
the waves. Rock pools often contain beautiful varieties of the 
more delicate species. Red alge will sometimes be found on 
the shady side of these pools. Sand-beaches are unfavorable 
to the growth of seaweeds, but fronds which have been carried 
long distances by the currents will frequently be found on such 
shores. ’ 
