. MARINE ALG^E OF BEAUFORT, N. C. 467 



i. Erythrocladia recondite Howe and Hoyt. PI. CXVI, fig. i; PI. CXVII, figs. 1-5. 



Erythrocladia recondite, Howe and Hoyt, 1916, p. 112, pi. 12, figs. 1-5; pi. 13, fig. i. 



Thallus endophytic or pseudo-epiphytic, creeping in the superficial cell walls of other algae, 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 0.2 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 i 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 algae and in the 

 stolons of hydroids growing on these, dredged from the coral reef offshore, Beaufort, N. C., August, 1914. 



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. 



3. Erythrocladia vagabonds Howe and Hoyt. PI. CXVI, fig. 2; PL CXVII, figs. 6-n. 



Erythrocladia Tiagabunda, Howe and Hoyt, 1916, p. 115, pi. 12, figs. 6-n, pi. 13, fig. 2. 



Thallus endophytic or pseudo-epiphytic, creeping in the superficial cell walls of other algae, 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 fillpendula dredged from the 

 coral reef at the same time as the Dictyota. 



Class 2. Floridese Lamouroux. 



Eur Floridece, 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 



