KEY TO THE, HIGHER ALG#, OF THE ATLANTIC COAST. 
H. Sporiferous nucleus subglobose, either simple or formed of 
many. nucleoli; numerous spores without order in a 
membranaceous mother-cell. (Fronds leathery, often 
large, and rarely adhering closely to paper.) . . 
I, Frond composed of polygonal cells ; often flat or ieee 
RHODYMENIACEA 
I. Fronds various, rarely truly fan-shaped; the ultimate 
structure being jointed filaments compacted together by 
gelatine, -s sites: tae ict EL ee CEA; 
J. Nucleus in an external, ovate or spherical conceptacle, : 
J. Nucleus not as ‘above; cylindrical, dichotomously forked, 
K. Cylindrical ; br anches mostly tapering towards base and 
3 apex ; a cellules very minei . 
GELIDIACER. 
K. Gi iat or flat ; surface covered with small cells ; 
branches not, tapering to.base (except in CHONDRIA) 
RHODOMELACEZ. 
K. Without above combinations ; frond flat in our species, ~ 
SPHAROCOCCOIDEZ. 
L. Namis in wart-like excrescences ; Per fan-shaped ; apices 
attenuate, of equal length, SPONGIOCARPEAS. 
` L. Nucleus immersed in the frond; apices blunt, 
: HELMINTHOCLADER. 
M. Frona cylindrical, at least the branchlets or younger parts artic- 
ulate oly hrnd 
M. 
Frond ie aableniate enki. ee en ee 
Frond elongated; main stem mostly inarticulate, but thickly 
te with fac jointed branching filaments which bear the 
5 
sya. 
Hy of frond, longitudinally aka, Saati. Teig red, and 
profusely branch Polysiphonia. 
Frond tessellated ae se or sie purple cells ; small— 
- about 1 inch high, . Bostrychia. 
Frond flat, etn obscurely ie . . Odonthalia: 
a 
o. Cylindrical; branches tapering toward the base, . Chondria. 
S Cylindrical; b branches not tapering to base, . +. Ehodomela. 
*%. one pinnate seal ; A to 4 inches high ; Corallina. 
elobes 
F rond a red i ga on igs in Smi water, Nullipora (2). 
AMER. NATURALIST, VOL, 
r 
481 
ae 
B 
HR poe = 
