MARINE ALGM OF BEAUFORT, N. C. 459 



Spatoglossum schroederi (Mertens) J. Agardh. PI. XCIII, fig. i; PI. XCIV, fig. 2 a and b. 



Ulva schraederi, Mertens, in Martins, 1828, pi. 2, f . 3. 



Taonia schraederi, Harvey, 1852, p. 107. 



Spatoglossum schrcederi, J. Agardh, i88oa, p. 113 (in part). 



Spathoglossum schraederi, De Toni, 1895, p. 249. 



A. A. B. Ex. No. 159 (Taonia schraederi). 



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, 1914 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, 18093, 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 son 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 

 only from the eastern coast of Africa and from the present locality. 



KEY TO SPECIES. 



Margin smooth or undulate, often lacerate, not serrate; no nerves running from midrib. 



i . D. polypodioides (p. 459). 



Margin serrate; nerves running from midrib to margins 2. D. serrata (p. 460). 



i. Dictyopteris polypodioides (Desfontaine) Lamouroux. PI. XCIII, fig. 2. 



Fucus polypodioides, Desfontaine, 1798, Tom. 2, p. 421. 

 Dictyopteris polypodioides, Lamouroux, 18093. 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 and from the midrib 

 on the flat surface of the frond ; numerous groups of short hairs scattered over the lamina; sinuses rather 



