458 BULLETIN OF THE BUREAU OF FISHERIES. 
distribution of the sori is the same as that of P. vickersie, but itis certainly closely similar (“P. variegata”’ 
and P. dubia being placed in the same group by Hauck on the basis of this character), and in other 
respects the two species seem identical. It seems, therefore, very probable that these belong to a single 
species. But, in view of some uncertainty regarding similarity in the arrangement of the sori and in 
view of the opinion expressed by Hauck that his material of P. dubia did not entirely agree with the 
“‘Zonaria variegaia’’ of Kuetzing, it has seemed better to keep the species separate until P. dubia can 
be more thoroughly studied. If the two are found to belong to a single species, both P. variegata (Kuetz.) 
Vickers and the present name must be reduced to synonyms. 
The type of the species here described is a tetrasporic plant from Fort Macon jetty, Beaufort, N.C., 
August 23, 1907. This and several cotypes have been deposited in the U. S. National Herbarium. 
The tetrasporangia, oogonia, and antheridia are borne on separate plants (the species being dicecious), 
and the sexual and asexual generations seem, from the results of Wolfe (1913, 1918), to alternate with 
each other as in Dictyota. There is evidence (Wolfe, 1918), for believing that the eggs may be fertilized 
before being discharged from the oogonium. Unfertilized eggs may commence their development 
parthenogenetically as in Dictyota, but apparently never (Wolfe, 1914, 1918), under such conditions, 
reach maturity. According to observations of Howe, 4 the tetrasporangia also may commence develop- 
ment without undergoing division, forming many-celled brood buds or propagula. The further history 
of these bodies is unknown. 
The portions of the cuticle covering the sori are raised by the developing tetrasporangia and oogonia 
as distinct indusia covering the fruiting areas (Pl. CXIV, figs. 1-3), while those covering the antheridia 
are not raised as distinct layers, and the antheridia accordingly appear naked. Although Bérgesen 
(1914) figures an indusium covering the antheridial sorus, the author, after careful study of sections 
of well-preserved material, has been unable to find these in any case. In spite of this discrepancy, 
the plants of Borgesen and those referred to here almost certainly belong to the same species. The 
indusia, when present, are very delicate and are finally ruptured by the developing sori; they are, 
consequently, often absent from mature fruits and frequently are not evident on dried plants. The 
tetrasporic and female plants closely resemble each other but can easily be distinguished by the fact 
that the tetrasporangia have about twice the diameter of the oogonia, mature tetrasporangia measuring 
41 to 90 by 47 to 108 mic. and the oogonia 27 to 45 by 36 to 63 mic. Frequently, moreover, all the 
oogonia on a single plant are of the same age, while the tetrasporangia, although usually of the same 
age in a single zone, are borne in successively younger zones toward the apical margins. There issome 
evidence that the sexual cells are borne in periodic crops at weekly intervals, but in other cases oogonia 
(or antheridia) of several different ages are borne on the same individual. 
Two other species of Padina are recorded from the West Indies. These, if found, 
may be distinguished from the present species by the following characters: 
P. sancte crucis Bérgesen.—Frond consisting of two cell layers, tetrasporangial sori in concentric 
zones above each alternate line of hairs. 
P. gymnospora (Kuetzing) Vickers——Frond consisting of three cell layers, tetrasporangial sori in 
concentric zones in middle of each alternate zone between the lines of hairs, sori not covered by indusia. 
Genus 3. Spatoglossum Kuetzing. 
Spatoglossum, Kuetzing, 1843, p. 339- 
Spathoglossum, De Toni, 1895, p. 246. 
Frond flat, ribbonlike, subpalmate-dichotomous, growing by groups of célls at the 
apices, surface uniform, zonations lacking; margin smooth or dentate; midrib lacking; 
cortex composed of a single layer of cells arranged in straight parallel lines; inner stratum 
composed of several layers of cells; spores produced four in a sporangium; sporangia 
scattered over both surfaces, occurring singly or several together in small groups; 
oogonia and antheridia produced on different plants; oogonia occurring singly, scattered 
over the surface; antheridia in small, scattered, inconspicuous sori. 
About eight species, in warm and tropical seas. 
@ The author is gratefully indebted to Dr. Marshall A. Howe for permission to refer to these unpublished results. 
© The author is indebted to Prof. J. J. Wolfe for considerable information regarding the life habits of Padina at Beaufort. 
