MARINE ALG OF BEAUFORT, N. C. | 467 
1. Erythrocladia recondita Howe and Hoyt. Pl. CXVI, fig. 1; Pl. CXVII, figs. 1-5. 
Erythrocladta recondita, Howe and Hoyt, 1916, p. 112, pl. 12, figs. 1-5; pl. 13, fig. 1. 
Thallus endophytic or pseudo-epiphytic, creeping in the superficial cell walls of other alge, con- 
sisting at first of free, irregularly radiating, and irregularly branching filaments, soon forming a more or less 
compact central region by the coalescence of the central filaments, the entire structure reaching a diameter 
of o.2 to 1.5 mm. and usually remaining single-layered; branching lateral or somewhat dichotomous, the 
lateral branches, especially in the younger parts, often spreading; cells varied and irregular in form, in 
surface view mostly oblong, quadrate, ovate, or fiddle shaped, often curved, forked, or irregularly one 
or two lobed, 8 to 25 mic. long, 3 to 12 mic. broad; male and female organs borne on the same individual; 
spermatia ovoid, 2 to 4 mic. in diameter, more or less exserted by slender stalks about 1 mic. broad; 
carpogonium furnished with a beak or trichogyne exserted about 4 to 8 mic.; sporocarp forming a single 
carpospore (or, rarely, two), these ovoid, oblong, or irregular, mostly 8 to 19 mic. in maximum diameter; 
nonsexual spores unknown. 
Endemic. 
Fairly abundant in the superficial cell walls of Dictyota dichotoma growing in the harbor, Beaufort, 
N. C., especially on Fort Macon jetties, summer and autumn; on Dictyota and other alge and in the 
stolons of hydroids growing on these, dredged from the coral reef offshore, Beaufort, N.C., August, ror4. 
This alga is entirely invisible to the naked eye and will not be seen even under the microscope 
unless a careful search is made. When seen, it appears as a more or less definite mass of clear, minute 
filaments closely adherent to the surface of the host. Its color is scarcely distinguishable, it apparently 
being so neutral in this respect as to show the color of the host. It can be made clearly evident by 
staining with iodine dissolved in potassium iodide. It will not be confused with any other species 
found in the harbor. It is unknown outside of this region. 
a. Erythrocladia vagabunda Howe and Hoyt. Pl. CXVI, fig. 2; Pl. CXVII, figs. 6-11. 
Erythrocladia vagabunda, Howe and Hoyt, 1916, p. 11s, pl. 12, figs. 6-11, pl. 13, fig. 2. 
Thallus endophytic or pseudo-epiphytic, creeping in the superficial cell walls of other algz, con- 
sisting chiefly of irregularly branching, uniaxially elongate, or irregularly radiating filaments, finally 
spreading over areas 0.75 to 2.25 mm. long or broad, often anastomosing or appearing to anastomose, and 
commonly forming here and there small irregular compact patches 2 to 6 cells broad; branching mostly 
lateral, rarely somewhat dichotomous, often spreading or rectangular; cells for the most part irregularly 
oblong in surface view, often curved or one or two lobed, 9 to 40 mic. long, 6.5 to 15 mic. broad; sporo- 
carps forming single carpospores (rarely two?), these ovoid, oblong, or irregular, mostly 12 to 25 mic. 
in maximum diameter; nonsexual spores unknown. 
Endemic. 
Fairly abundant in the superficial cell walls of Dictyota dichotoma dredged from the coral reef off- 
shore, Beaufort, N. C., August, 1914. 
This species is not visible to the naked eye and will not be noticed, even under the microscope, 
unless a careful search is made. Staining with iodine dissolved in potassium iodide will help to 
make it evident. It has not been found in the harbor. If it should be found there, it will not be 
mistaken for any other alga except E. recondita. From this it is distinguished by its more straggling 
habit, its larger cells, and its more rectangular branches. It is not known from any other region. 
Plants apparently belonging to this species were found on Sargassum filipendula dredged from the 
coral reef at the same time as the Dictyota. 
Class 2. Florideze Lamouroux. 
Ew- Floridee, De Toni, 1897, p. 33. 
Thallus multicellular, exceedingly various in size, habit, and structure; asexual 
propagation by nonmotile spores produced (usually four—tetraspores, sometimes one, 
two, or many) in special sporangia; tetrosporangia divided zonately, cruciately, or 
triangularly; sexual reproduction by nonmotile spermatia and eggs borne in special 
antheridia and carpogonia, respectively; antheridia variously formed, producing numer- 
ous minute spermatia; carpogonia bearing single eggs which, when fertilized, give rise 
