HOWE AND HOYT: MARINE ALGAE FROM BEAUFORT, N. C. IO9 



one, two, or three short-stalked lateral sporangia. The exterior 

 filaments are 10.5-15.5 fj, in diameter and their cells are mostly 

 2-4 times as long as broad, though often much shorter at the 

 base of a terminal hair. The interior filaments have about the 

 same diameter as the exterior. The plurilocular sporangia are 

 40 — 78 /i X 14-36 fjL. Since its discovery in France, Streblonema 

 solitarium has been reported from southern England and Ireland,^ 

 but, so far as we know, has not hitherto been recognized as Ameri- 

 can. It is, however, to be expected wherever its host occurs. 



Phaeostroma pusillum sp. nov. 



Thallus irregular in outline or suborbicular, 0.3-0.8 mm. in 

 diameter, the component closely repent filaments and their 

 numerous curved or sinuous branches forming a moderately 

 compact, more or less pseudoparenchymatous unistratose mem- 

 brane, its margins commonly irregularly lobed or show^ing discrete 

 filaments, such filaments with frequent subdivaricate, often 

 recurved or incurved, occasionally pseudo-anastomosing branches; 

 vegetative cells subcylindric or more often curved or of irregular 

 diameter, mostly 10-16 yu X 5-10 /x, usually 1.5-2.0 times as 

 long as broad; chromatophores suborbicular, irregularly discoid, 

 or somewhat baculiform, commonly more or less fused, numerous 

 and crowded, occasionally substellate-conglobate, or less numerous 

 and somewhat reticulately disposed; hairs occasional, 8-10 /x in 

 diameter, showing at the base 4-6 short cells (5-10 ix long) ; pluri- 

 locular and unilocular sporangia on separate individuals; unilocular 

 sporangia (i) scattered or aggregated, obovoid or subglobose, 

 8-16 IX in diameter, sessile, or, (2) by subdivision and proliferation 

 of the fundamental cell and by coalescence, forming elevated 

 submoriform sori 16-48 fi in diameter, the ultimate sporangia then 

 smaller, mostly 5-8 ix in diameter, and often more angular; 

 microspores about 1.5 ^ in diameter; plurilocular sporangia scat- 

 tered and solitary or loosely gregarious, ovoid, ellipsoid, sub- 

 spheric, or subconic, sessile, suberect, 22-27 M X 15-18 m, about 

 7-9 loculi measuring the length of the sporangium and 4 or 5 its 

 maximum width. [Plate ii, figures 1-9.] 



On Dictyota dichotoma and stolons of Campanularian h^'droids 

 thereto attached, dredged in 133^-14 fathoms of water on reef 

 about 23 miles ofT shore from Beaufort, North Carolina, August 

 II, 1 914, by Lewis Radcliffe. One of us (W. D. Hoyt) has ob- 

 served it also on Spyridia sp., collected at the same time and 

 place. 



1 Batters, Cat. Brit. Mar. Alg. 30. 1902. 



