480 KEY TO THE HIGHER ALGZ OF THE ATLANTIC COAST. 
in the frond, rarely contained in proper receptacles; each tetra- 
spore enveloped in a pellucid skin, and at maturity splitting into 
four sporules. Antheridia filled with yellow or hyaline corpuscles. 
Ours all marine A PRA and ei below low water 
noce e a 
mark. 
A. Frond calcareous, riia; its cells containing Carbonate vs 
Lime, i . . . . CORALLINACE TTE 
A. Frond expanding hema lichen-like, but not calca- | 
Gs. a. - « « « SQUAMARLA. y 
A. Frond not calcareous nor lichenoid, . ' B 
B. Frond mostly cylindrical, partly or entirely artioulate, c 
B. Frond not articulate anywhere, i G | 
C. Nodes much constricted, . ; D 
C. Nodes not specially osiavicted, „E 
D. Joints obvious throughout, long in ithe main seme on = 
gradually shorter above, spherical at the tips; color 
bright, sometime gold-tinted, . . GRIFFITHSIAM 
CERAMIACE®. d 
D. . Terminal joints not spherical : colors duller, often greenish, 
cuamp1a in LAURENCIACEE. 
Sporiferous nucleus in external spherical conceptacles : axis 
Fi 
polysiphonous (of 4 or more age joints not distinct 
on older parts of frond, . HODOMELACE2. 
E. Avis monosiphonous : me a obvious : colors mostly 
. + 
bright, ue 
F. Branches beset with ‘dor, fae, ‘mostly simple “filam A 
SPYRIDIACEE. ! 
F. Not as above ; mostly dae Kg, frond sometimes 
two edged, . CERAMIACEZ. 
G. Frond flat, with an evident midvein, 
SPHÆROC 
G. Frond without a midvein, 
H. Sporiferous nucleus sondteting of tufted sporestre 
tached to a placenta; single spores in 
spore thread, or only in the terminal cell. 
rarely flat or — PRY less — in 
than the next.) ; i s 
eat 
-oocom a 
