MARINE ALG OF BEAUFORT, N. C. 459 
Spatoglossum schroederi (Mertens) J. Agardh. Pl. XCIII, fig. 1; Pl. XCIV, fig. 2a and b. 
Ulva schrederi, Mertens, in Martins, 1828, pl. 2, f. 3. 
Taonia schrederi, Harvey, 1852, p. 107. 
Spatoglossum schrederi, J. Agardh, 1880a, p. 113 (in part). 
Spathoglossum schrederi, De Toni, 1895, p. 249. 
A. A. B. Ex. No. 159 (Taonia schrederi). 
P. B.-A. Nos. 326, 2027. 
Frond membranaceous, thin, dichotomous, or sometimes subpalmate with approximate segments 
and irregularly decompound above by new segments sprouting from the margins; these segments some- 
what contracted at their bases; margin entire in younger portions, later distinctly distantly serrate; 
color yellowish brown. 
Florida to Brazil; West Indies; Bermuda; Guadeloupe. 
Beaufort, N. C.: Three plants in one small mass on Fort Macon jetty, August, 1906; few fragments 
dredged from coral reef offshore August, r914 and 1915. ‘ 
This species often closely resembles Dictyota dichotoma, from which it is easily distinguished by 
its groups of initial cells at the apices of the branches and by its serrate margins. All three of the plants 
from Beaufort Harbor were fruiting abundantly, bearing numerous tetrasporangia scattered thickly 
over both surfaces. The plants from the coral reef have decidedly dentate margins, while those found 
growing in the harbor have almost smooth margins with only a few ciliate projections. 
This is the only species of this genus known from North America, Spatoglossum areschougii J. Ag. 
(which has been listed for this continent), now being regarded as belonging*to the present species. 
This is the northern known limit of the species and of the genus. 
Genus 4. Dictyopteris Lamouroux. 
Dictyopteris, Lamouroux, 1809a, p. 129. 
Haliseris, De Toni, 1895, p. 253- 
Frond erect, flat, more or less regularly dichotomous, growing by groups of cells at 
the apices, surface uniform, zonations lacking; provided with a conspicuous midrib and, 
in some species, with veins running from the midrib to the margins; lamina transient 
in the basal portion, the frond finally consisting in this region of the persistent midrib 
forming a stemlike structure; cortex composed of a single layer of cells; inner stratum 
composed of several layers of cells; spores produced four in a sporangium; sporangia 
occurring in sublinear or spotlike sori on both sides along the midrib on both surfaces 
of the frond; oogonia and antheridia produced on the same plant; oogonia occurring 
singly, scattered over both surfaces; antheridia in small inconspicuous, scattered, slightly 
sunken sori, especially in the region of the midrib. 
About 14 species, in warm and tropical seas. 
It is interesting that both the species found at Beaufort should be new to North 
America. D. serrata has an especially interesting distribution, being previously reported 
ouly from the eastern coast of Africa and from the present locality. 
KEY TO SPECIES. 
Margin smooth or undulate, often lacerate, not serrate; no nerves y= pie from midrib. . 
: aH Dp: polypodioides (p. 459). 
Margin sermate: nerves seeaiiing from midrib % margins. Se Sickie ie Tania CL Cae 2. D. serrata (p. 460). 
1. Dictyopteris polypodioides (Desfontaine) Lamouroux. Pl. XCIII, fig. 2. 
Fucus polypodioides, Desfontaine, 1798, Tom. 2, p. 421. 
Dictyopteris polypodioides, Lamouroux, 1809a, p. 131. 
Haliseris polypodioides, De Toni, 1895, p. 254. 
Frond 7.5 to 72 cm. long, 0.4 to 1.2 cm. wide, on a more or less elongated subterete stipe; color 
olive brown; repeatedly dichotomous, with occasional branches arising laterally ahd from the midrib 
on the flat surface of the frond; numerous groups of short hairs scattered over the lamina; sinuses rather 
110307°—21——30 
