Pacific Species of Antithamnion — TOKIDA and INABA 
129 
pinnae present a feathery appearance which 
reminds one of the beautiful plumes from the 
gorgeously eyed train of the peacock, inas- 
much as they bear distichous opposite pin- 
nulae on each axial cell (except for the basal 
one) and one large gland cell glittering at 
their apices. The Japanese name proposed 
for this species is based on that appearance. 
The reproductive organs unfortunately have 
not been discovered in our specimens. The 
description of the species given here is 
based upon our sterile specimens collected at 
Shirahama. 
The writers owe the present identification 
to the suggestion of Prof. Y. Yamada, of the 
Faculty of Science in Hokkaido University, 
who once made a comparison of the Japa- 
nese specimens (which were then provision- 
ally referred to Acrothamnion pulchellum ) 
with Harvey’s Austr. Alg., No. 539 ( Calli - 
thamnion pulchellum Harv. ) , or the type 
specimen of Acrothamnion pulchellum, in 
Harvey’s herbarium at Dublin, Agardh’s her- 
barium at Lund, etc. (cf. Yamada and Ina- 
gaki, 1935: 37). He informed us that the 
authentic specimens of the species when seen 
under the microscope attracted his special at- 
tention by their possession of the quite char- 
acteristic apical gland cells. On the other 
hand, it is curious that we find no description 
of that organ in the diagnoses of the genus 
and the species given by Harvey, J. Agardh, 
De Toni, and Lucas & Perrin, if " favellus ,” 
which was described by Harvey as "favellis 
simplicibus rachidem plumulae terminali- 
bus,” is really comparable with the cystocarp 
and not with the gland cells as illustrated by 
J. Agardh (1892: Fig. 10) in a simple and 
equivocal figure. This figure seems to have 
nothing to do with the cystocarp but reminds 
us of an inflated axial cell of a pinna infected 
by a parasitic fungus (cf. Tokida, 1932: Fig. 
5 b). "Pinnula . . . adparenter truncata,” il- 
lustrated in the same work of J. Agardh (Fig. 
9), resembles quite well a simple accessory 
pinna lacking an apical gland cell in our 
Japanese plant. "Pinnulae steriles (ad *),” 
illustrated in Figures 6, 7, and 8, resemble ab- 
normal lower pinnae lacking gland cells in 
our plant (cf. Figs. 10 b and lOe in the pres- 
ent paper). The arrangement of the pinnae 
in our plant, which is distichous with two 
opposite compound pinnae spreading on the 
same plane, or, more frequently, tristichous 
with a more simply constructed pinna in 
addition to the opposite ones just mentioned, 
seems to agree with the description of the 
pinnae of Callithamnion pulchellum given 
by J. Agardh (1876), which runs as fol- 
lows: "pinnis geminis conformibus distichis 
opposite pinnulatis, aut ternis una dispari 
simpliciore.” As to the validity of the tetra- 
sporangium-bearing simple and subfiliform 
accessory pinnula, which was described and 
illustrated by J. Agardh (1892: Figs. 6, 7, 
and 8 ) , as a character of generic importance, 
we are inclined to harbour a strong doubt 
since we could observe sessile tetrasporangia 
on a fragment of Harvey’s original specimen 
of Callithamnion pulchellum (Alg. Austr. 
Exsicc., No. 539D) through the most gen- 
erous kindness of Mme. Valerie May of the 
Division of Fisheries, Marine Biological Lab- 
oratory, Cronulla, New South Wales, Aus- 
tralia. In April, 1948, the senior author 
received a letter from her answering his re- 
quest to compare some figures of the Japa- 
nese plant drawn by himself with the authen- 
tic specimens of Acrothamnion pulchellum 
J. Ag. Mme. May kindly enclosed in her letter 
a fragment of Harvey’s specimen deposited 
in the National Herbarium of New South 
Wales, Sydney. In examining the fragment 
under the microscope, it was quite satisfac- 
torily ascertained that our Japanese plant 
coincides with Harvey’s species in every mor- 
phological characteristic. As the fragment 
fortunately bears tetrasporangia, the authors 
wish to give here a thorough description and 
illustrations of them. 
The tetrasporangia-bearing branch is 
marked by having frequently a couple of 
