KEY TO THE HIGHER ALGÆ OF THE ATLANTIC COAST. 399 
tacles; each spore enveloped in a pellucid skin, simple or finally 
separating into two, four or eight sporules. Antheridia, or 
transparent cells filled with orange-colored, vivacious corpuscles, 
moving by means of vibratile cilia. 
Marine, often of large size, mostly between tide marks, A 
A. FROND LEATHERY OR MEMBRANACEOUS, FORMING A COM- 
PACT URLLULAN BUBSTANOR, o o a roura e 
A. FROND OF JOINTED FILAMENTS WHICH ARE EITHER FREE OR 
UNITED IN A COMPOUND BODY, ee E E R L ob Ar Ve 
B. Spores in spherical cavities in the frond; air vessels com- 
monly present ; large, tough plants, . FUCACEA. D 
B. Spores in indefinite cloud-like patches on the surface 
of the frond, which is usually large and stipitate, 
sometimes deeply divided, but never truly branched, 
LAMINARIACEÆ. 
rej 
B. Spores attached to external jointed filaments; ours, slen- 
er deep water species becoming blackish-green in 
drying, cied e a BPOROCHNACR Æ: B 
B. Spores < definite groups (sori) on the surface of the 
frond; fronds smallish, juiceless, the surface netted 
with e cella, o 03,2 6) ¢ DIOTYOTACEA: H 
C. Spores immersed ; fronds not jointed, except in a few small 
parasites in which the filaments are connected at 
baa LS Ce ., > CHORDA RIACE E. 
Pi 
C. Spores external >; fronds either obviously jointed or else sur- 
rounded by whorled branchlets, ECTOCARPACEÆ. 
D. Frond leafy; air vessels stalked separate Sargassum. 
D. Frond leaf-like belo ow; air vessels in EEES branchlets, pod-like, 
several celled, Halidrys. 
D. Fron mx seams’ i receptacles filled with mucous; nit vessels, x 
Fucu 
nt, no 
E. Hoi seder, ri wink of delicate Hanpi at the stray 
Arthocladia. 
E. Frond pinnate, solid, . Caters ee ea. ~ Desmarestia. 
F. Frond f flat, With a mddvein. r E a ewe wg 
F. Frond flat, without a midvein, . . -- +--+ + + Laminaria. 
NK i som 
