422 
PACIFIC SCIENCE, Vol. VIII, October, 1954 
Key to the Species of Gelidiella 
1. Plants 2-3 cm. tall, branches arching. . . . 
G. acerosa 
Plants 1 cm. tall or less 2 
2. Plants tufted, to 1 cm. tall 
G. myrioclada 
Plants minute, partially creeping, 1.5-2 
mm. tall 3 
3. Basal creeping branches attached at inter- 
vals G. tenuissima 
Basal creeping branches attached by rhiz- 
oids along their entire length . . G. adnata 
Gelidiella acerosa (Forsk.) Feldmann and 
Hamel 1934: 533. Fucus acerosus Forskal 
1775: 190 (Red Sea). Echmocaulon acernsum 
(Forsk.) B0rgesen 1932: 5, pi. 1, fig. 3 
Fig. 33g 
LOCAL DISTRIBUTION: On rocks slightly ex- 
posed at low tide, Sta. 4 (11204); abundant 
and commonly collected for food from rocks 
at low-tide level, Sta. 10 (11340). 
Gelidiella myrioclada (B0rg.) Feldmann 
and Hamel 1934: 533. Echimcaulon myrio- 
cladum B0rgesen 1934: 5, figs. 4, 5 (Bom- 
bay, India) 33^ 
LOCAL DISTRIBUTION: Tufted, to 1 cm. tall, 
on rocks, Sta. 10 (11341). 
. My fertile plants are in complete agree- 
ment with B0rgesen’s account of the Indian 
type. 
Gelidiella tenuissima Feldmann and Hamel 
1936: 102 (Mediterranean France) . Gelidiella 
pannosa (Bornet) Feldmann and Hamel 
1934: 534, figs. 1, 2. Gelidium pannosum 
Bornet 1892: 267 (non G. pannosum Gru- 
now); Weber van Bosse 1921: 223, fig. 68, 
pi- 7, fig. 3 33^ 
LOCAL DISTRIBUTION: Forming a coarse vel- 
vet of filaments 1.5-2 mm. long on rather 
high coral rocks, Sta. 1 (11302). 
These plants are in particularly good agree- 
ment with the Indonesian specimens of Weber 
van Bosse. In the few stichidia examined, the 
sporangia were not in very clear transverse 
rows as is usual in the species. 
Gelidiella adnata sp. nov. 
Fig. 33/ 
Thallis minutis, repentibus, e filamento 
basali, cylindrico, prostrato, 40-70 ju diame- 
tro, per totam superficiem inferiorem ope 
seriei densae rhizoidum brevium adjunctis, 
per superficiem superiorem filamenta vegeta- 
tiva baud fere ramificata 35-60 /x diametro, 
1. 5-2.0 mm. alta, atque stichidia tetrasporan- 
giaha brevia, erecta, emittentibus; -tichidiis 
plerumque in pedicellis brevibus gracilis 
busque, 80-90 /x lads, lanceolatis, ad 400-500 
/X longis crescentibus, sporangiis in stratis 
transversis fere quaternis dispositis. 
Thalli minute, creeping on rock surfaces, 
consisting of a cylindrical, prostrate basal fil- 
ament 40-70 fjL in diameter attached along 
its entire undersurface by a dense rank of 
short rhizoids, this giving off along its dorsal 
surface erect, usually unbranched, vegetative 
filaments 35-60 ju in diameter, 1. 5-2.0 mm. 
tall, and short, erect, tetrasporangial stichidia; 
stichidia mostly on short, slender pedicels, 
80-90 fx broad, lanceolate, becoming 400- 
500 II long, the sporangia usually arranged 
in groups of four in regular transverse tiers; 
tetrasporangia about 23 ii in diameter, tetra- 
hedrally divided; cortical cells in surface view 
longitudinally elongated and tending to be 
arranged in rows. 
type: Holotype is Dawson 11309, Feb. 13, 
1953, in the U. S. National Herbarium. 
Type Locality: Growing on intertidal rock 
surfaces with Herposiphonia along rocky shore, 
Sta. 9. 
This minute Gelidiella differs from similarly 
small G. tenuissima by its adnate basal branch 
and by the pedicellate stichidia arising from 
