Fig. 3. A and B, Polysiphonia? sp. (scale for B applies to A as well). C, Polysiphonia exilis, prostrate 
branch and erect branches. D and E, Polysiphonia tepida. 
Algae minutae, ramos prostratos 40-60ja diam. et 
segmenta aequa longa ac lata habentes, rami per 
rhizoidea unicellularia, ut cellulae discretae separata, 
affixi; rami erecti ad 4 mm alt., 40-5 Op, diam., pler- 
umque non ramosi, segments plerumque ac longis ac 
latis aut brevioribus; cellulae peri centrales 4 in ramis 
prostratis et 6-9 in ramis erectis; trichoblastae rarae 
elementariaeque, primordiis vulgo uno in unoquoque 
segmento in ramis erectis prostratisque, in spira ordi- 
natis nisi in ramis tetrasporangialibus; tetrasporangia 
in serie brevi non spirali; rami spermatangiales e 
primordio trichoblastae toto enascentes; cystocarpi non 
observati ; plantae in collo testudinis marinae colentes. 
type: T. 609, tetrasporic, spermatangial, 
scraped from the neck of a sea turtle, Chelonia 
mydas. It was collected by Roy T. Tsuda at Lay- 
san I., Hawaii (25°48'N, 171°44'W), Dec. 8, 
1963. It is represented by a single glucose 
mount. 
The spiral arrangement of trichoblasts and 
scar-cells, which are unilateral only on tetra- 
sporangial branches, and the cicatrigenous ori- 
gin of erect branches, are features which exclude 
this alga from the genus Lophosiphonia. 
No additional collections are available for 
study, but no other species of Polysiphonia 
closely approximates the distinctive features of 
this alga, especially the epizoic habitat, the 
minute size, the variable number of pericentral 
cells, and the origin of spermatangial branches 
from the entire trichoblast primordium. 
Polysiphonia ? sp. 
Fig. 3 A, 3 B 
Plants to 1 cm high with prostrate branches 
200— 220p in diameter, attached by rhizoids 
