Marine Algae from Eniwetok — Dawson 
adaxial, one or several in the lower half of a 
lateral branchlet in mid-parts of thallus. 
Thallis 4-5 mm. aids, partibus inferis semi- 
prostratis a ramulis lateralibus mutatis in 
discis adhaerentibus, axilis principalibus 80- 
90 n diametro ecorticatis et cellulis l-lVi-plo 
longioribus quam latis, ramulis lateralibus 
20-30 fx diametro laxis subattenuatis sed ob- 
tusis plerumque simplicibus curvatis alternatis 
plerumque contorte affixis, tetrasporangiis 
tripartitis ca. 40 /x diametro sessilibus ad- 
axialibus in dimidia parte infera ramulae 
lateralis in media thalli affixis. 
type: Dawson 13695, on shells and dead 
coral from a depth of 6-10 feet in the lagoon, 
south end of Parry Island, Eniwetok Atoll, 
August 21. 
additional material: D. 13992, under 
rocks on reef along passage; D. 13950a, 
epiphytic on Halimeda and Caulerpa\ D. 
13997c, epiphytic on Halimeda\ D. 13698a. 
This species is seemingly nearest to Calli- 
thamnion paschalis B^rgesen (1924: 294, fig. 
35) from Easter Island, but is neither con- 
sistently distichously branched like that spe- 
cies nor with the tetrasporangia borne in the 
terminal branchlets of the main axes. 
Wrangelia anastomosans Yamada 1944: 41, pi. 
7, fig. 2 (Ant Atoll, Caroline Islands) 
Fig. 25 d 
P. 79a, Igurin Is. tide flats in shallow water, 
11/4/54. 
Wrangelia argus (Montagne) Montagne; 
Dawson 1954: 444, fig. 54g; Dawson 
1956: 56 
D. 13941. This material agrees with the 
details by which Tseng (1942) differentiates 
W. argus from W. tayloriana Tseng, and lacks 
the more or less complete cottication of W. 
penicillata. The involucral filaments are about 
11-13 ix in diameter, of 3 to 5 cells, often 
dichotomous and strongly curved. The tetra- 
sporangia are 70-80 /x in diameter at maturity. 
119 
Wrangelia penicillata C. Agardh 1828: 138 
(Adriatic Sea); Taylor 1950: 136 
T. 46-336. Not collected again. 
Griffithsia ojxalis Harvey 1862, vol. 4: ph 203 
(King Georges Sound, West Australia); 
Abbott 1946: 440, pi. 1, figs. 1-4, pi. 2, 
figs. 1, 2 
Fig. 2 6a-d 
D. 14012, fertile. Several other sterile col- 
lections were made of a Griffithsia which is 
probably this species. 
Griffithsia tenuis C. Agardh; Dawson 1954: 
450, fig. 56e; Dawson 1956: 56 
D. 13702, 13785, 13950d, 13956, 14029. 
Neomonospora pedicellata var. tenuis Feldmann- 
Mazoyer; Dawson 1954: 450, fig. 56a 
D. 13610a. 
Ceramium clarionense Setchell and Gardner; 
Dawson 1954: 448, fig. 55k; Dawson 1956: 
54 
D. 13767. This material, epiphytic on Tur- 
binaria , is sterile, but the circinate tips and 
Fig. 26. a-d, Griffithsia ovalis : a , Vegetative cells 
with involucrate tetrasporangia between articulations, 
X 30; h, habit of part of a specimen with a rhizoid, 
X 16; c, involucrate tetrasporangia near the top of a 
plant, X 26; d, a mature' tetrasporangium on a pedicel, 
X 300 (all after Abbott). 
