KEY TO THE HIGHER ALGÆ OF THE ATLANTIC COAST. 489 
g 
Green — cell-walls membranous; fresh water — chiefly or 
Tey ER o DESMIDIACEZ.* 
. Yellow brown; cell-walls silicious. DIATOMACEZ.* 
Frond sponge-like, of densely interwoven filaments, . Codium. 
Filaments free, plume-like, pinnately branched, . ryopsis. 
Filaments numerous, tufted or matted at base, free shoe e, irreg- 
ularly oe itie Sao <n OMCRER Oe 
z EL A i wee r: DARGIN: 
rond flat, ni or pa ft, si ancat e Porphyra: 
a rond flat, sometimes PER wile pp; . 
Frond tubular, often branched, . . ee Saanaa: 
Filaments tufted, branched, . » Cladophora 
Filaments unbranched; nodes ee aie sted. . Chetomorpha. 
filaments unbranched; constricted at the. nodes; a very 
short, : Hormotrichum. 
Filaments jong: flexible, bandied rela. E NERE E i Poros 
Filaments short, tufted, erect, tixed at base, - + Calothrix 
Filaments rigid, needle-shaped, lying loosely in a mucous matrix; 
vividly oscillating; commonly floating, . . Oscillatoria.* 
Fronds erect, TEPEE clothed with soft hairs, . . . 14 
Not much b d in, $ 
Common Gai reac with a bright glassy Tastee when on < 151 
Fruit— minute dark parais granules, arranged in fours, - . 152 
In fresh or salt water for rming large dark purple patches, cio eit air LO 
Forming a minute rosy down on Chondria, ete... . 154 
Frond never branched, large and bag-like when rally grown, . 155 
Frond bra nched; branches simple, obtuse, . - . . 156 
Frond branched; branches beset with ee og ps LE gra 
Fronds slender, tuft ed, . .- 157 
Fronds. very fine and feathery ; eshphiets BER sonia- 
ike, 7 ‘ 
Membrane formed aS a oaa laser of pa 
Membrane formed of as ingle layer of cells; eigen ea 
_ frond very delicate, saccate while young, becoming cleft; 
adheres closely to paper 161 
Frond lanceolate, compaia. of two closely applied n membranes; 4 
adheres to o paper. . yt 
Frond polymorphous, flat, aaea Sag ren ; 
Filaments rigid, dark green tufted, cell walls eg Joints 3 to 
4 times s long as broa 
Paent, ce forming ua BE fastigiate pale g green tufts, 
Filaments loosely tufted, stout, scarcely collapsing when drawn 
from the water; vivid green; joints 3 to 6 times as long as 
ia | 
eee et a ee E 
See ; . * Omitted. 
Dee wei Ri TS SEN i 
. 
HHeets HAA g 
be} by 
Sg 
5 
a 
Be 
5, 
3 
See 
kn MH ohop kun Hey 
WWOOORARBEMAS 
gp 
SARAR 
as CE: 
