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l92o] Setehell-Gardner: Melanophyceae 661
st rich us structure. Z. Diesingiana J. Agardh is more prostrate and
coarser. The Japanese plant illustrated under this name by Okamura
(1907, pi. 4, figs. 1-10) has paraphyses with peculiar swollen terminal
cells. Zonaria intemtpta (Lamour.) J. Agardh, from the Cape of
Good Hope, has very narrow divisions and has paraphyses with short,
swollen cells above, as in ours, but the terminal segment of each divi-
sion of the frond is peculiarly truncate and enlarged above (cf.
Phycopteris cuneata Kuetz., Tab. Phyc, vol. 9, 1859, pi. 67, fig. II).
The structure of the frond is also very different, as may be seen from
Kuetzing's figure quoted above.
64. Padina Adans.
Fronds plane, ecostate, flabellate, entire or branched, differentiated
into two kinds of tissues, a single surface layer on either side consist-
ing of color bearing rectangular cells, and a central tissue, medulla, of
several layers of somewhat elongated cells with few chromatophores
growth in length by divisions of many marginal cells ;
margin scrolled,
or inrolled ; reproduction sexual, heterogamous, and asexual by aplano-
spores ; the reproductive organs at times developed in transverse zones
on the upper parts of the fronds and the antheridia in longitudinal
sori, on the same frond as the oogonia.
Adanson, Fam. II, 1763, p. 13 (fide De-Toni).
The " Peacock 's-Tail" algae are well-known tropical species whose
specific limits require careful study and consideration. The genus is
readily distinguished by its involved meristematic margin and by its
having the sori only on one side (the upper) of the frond.
Padina Durvillaei Bory
Plate 93
Fronds 10-22 cm. high, membranaceous to decidedly coriaceous,
highly stupose for considerable distance above the base, repeatedly
and irregularly branched by splitting of the blade more or less deeply,
the lobes laciniate to reniform-flabellate ; thickness of frond varying
from 18 cells, at the base, to 1 cell, at the broad inrolled margin, for
the most part 8-12 cells thick; the flabellate portion of the frond
marked distinctly by numerous, narrow, concentric bands of hairs;
color dark brown, dark green to almost black on drying; sori of
oogonia and aplanosporangia distributed unevenly over both sides of
;