1918] MACCAUGHEY—HAWAIIAN ALGAE 123 
Coleosphaeriopsis halophila Lemm.—Colonies spherical, gelat- 
inous, hollow, known only from the lagoon of Laysan Island. 
Merismopedium glaucum (Ehrenb.) Naeg.—Colonies flat, free 
floating, in shallow, sluggish water, such as rice fields, taro loi, etc.; 
sometimes very abundant, especially in late summer (Oahu). 
CHAMAESIPHONACEAE 
Xenococcus laysanensis Lemm.—Epiphytic, disk-shaped colo- 
nies; collected on marine algae at Laysan Island. 
X. Kerneri Hansg.—Colonies irregularly expanded, crustaceous; 
fairly abundant in ditches and taro patches throughout the low- 
lands; sometimes epiphytic. 
Chamaesiphon curvatus Nordst.—Epiphytic; collected among 
filaments of Cladophora longiarticulata in taro patches and ditches; 
not common; var. elongatum Nordst. is found in similar situations. 
OSCILLATORIACEAE 
Oscillatoria sancta Kuetz.—Colonies or plant mass dark lead 
colored, ‘‘becoming violet when dried and tinting the paper a 
beautiful violet’? (T1tpEN); forms a reddish brown or grayish 
skin on the wet sides of cliffs, waterfalls, ditches, and other moist, 
earthy places. 
O. Bonnemaisonii Cruan.—Trichomes form loose and regular 
spirals; epiphytic on marine algae in Laysan Island waters; mixed 
with other algae, floating in lagoons within the reefs, Hawaii and 
other islands. 
O. corallinae Gomont.—Trichomes gregarious, forming a fine, 
delicate coating on the surface of larger algae; collected at Laysan 
in washings from marine algae. 
O. laetevirens Crouan.—Plant mass thin, membranaceous, bright 
blue-green; abundant, forming a delicate stratum covering the bot- 
toms and sides of tidal pools in rocky places along the platform 
reefs; also collected among washings from marine algae at Laysan. 
O. formosa Bory.—Plant mass dark blue-green; common on wet 
cliffs and near waterfalls, in the montane rain forests; also on 
the walls of wet caverns, near the mouths; these latter situations 
are often rich in blue-green algae. 
