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inconspicuous. Prominent among the types of this class selected 
for exhibition in the synoptic collections are two specimens 
of Laminaria longicruris from Nova Scotia, one of which when 
fresh measured thirty-two feet in length, including blade and 
stalk. e Laminarias are sometimes called ‘“ oar-weeds”’ or 
“ devil’s-aprons,”’ or are more often referred to in a general way 
as ‘“‘kelps.”” One species of kelp is found occasionally about 
New York City but they are more at home in more northern 
waters. They grow attached to rocks, stones, and wooden piers 
from just above the low water mark down to where the water is 
twenty feet deep or more at low tide. But the climax of all the 
marine plants in point of size is easily the plant known to botan- 
ists as A/acrocystis — also often spoken of as the “ great kelp,” a 
name which it deserves even in comparison with the other kelps of 
giant dimensions. This plant, whose chief home is in the Pacific 
Ocean and especially along the western shores of the American 
continents, is attached to the bottom by a widely spreading and 
branching holdfast. It prefers water that is perhaps from thirty 
to seventy feet in average depth. From the strong holdfast a 
long naked stalk arises to the surface of the water, where floats 
the main part of the plant, consisting of a much elongated stem- 
like portion bearing large alternate toothed ‘ leaves.” Eac 
“leaf” has a stalk of its own, a part of which is an inflated 
vesicle. The vesicles are filled with air or gas and keep the plant 
afloat. Growth in this plant is mostly in the apical region and 
it may continue to elongate here until it has reached an enor- 
mous length. Various more or less credible stories are told 
about it ; the eminent botanist Sir Joseph Hooker, who enjoys an 
excellent reputation for accuracy and veracity, estimated the 
length of a single living individual once seen by him at seven 
hundred feet. 
The olive-green rockweeds, familiar to all who are accustomed 
to visit our seacoast from New Jersey northward — especially 
where there are rocks and stones along the shore — belong with 
the brown seaweeds. The rockweeds are represented in the show- 
cases by several genera and species and accompanying plates 
