256 F. B0RGESEN 



The basal part of the plant consists of a monostromatic tissue composed 

 of irregularly curved and ramified creeping filaments growing gradually more 

 or less tightly together. The cells of the basal layer are about 15 — 20 (J. thick 

 and 24—28 [A long. From these cells erect filaments arise. These are mostly 

 simple having a zone of growth somewhat above their base. Here the cells 

 are short with intercalary divisions. Upwards they gradually increase in length, 

 the chromatophores become less developed and the ends of the filaments become 

 hairlike, gradually dying off. 



These assimilating filaments measure about 8 — 10 [j, at their base, the 

 length of the cells being 25 — 30 p.. In the zone of divisions the cells are about 

 16 jx wide and mostly shorter than long. Keeping about the same width the 

 upper cells attain length of about 65 |x. The filaments are up to 1 mm long. 

 Most of the assimilating filaments are simple but sometimes carry a single 

 equally developed branch near their base; in the upper part they are always 

 undivided. Near the base they also carry short filaments bearing terminal 

 plurilocular sporangia. These filaments consist mostly of a single or of two 

 cells. Now and then, too, a plurilocular sporangium is borne on a short filament 

 arising directly from the basal filaments. 



In one specimen (Fig. 6 b) two small sessile gametangia were observed at 

 some distance from the base and one sporangium on each of the filaments, 

 somewhat recalling the genus Gononema Kuck. und Skottsb. 1 The plurilocular 

 sporangia are ovate-spindleshaped, about 100 |x long and 25 u. broad. In the 

 fresh divided cells, the chromatophores form several roundish discs, in the 

 older cells oblong bodies or short staffs. 



This new Ectocarpus evidently comes near Compsonema fasciculatum and 

 C. coniferum, described by SETCHELL and GARDNER in Phycological Contribu- 

 tions II to IV (University of California Publications, vol. 7, 1922), but the present 

 plant is much larger and also shows several differences in the shape of sporangia, 

 assimilatory filaments etc. 



Area of distribution: Endemic. 



E. breviarticulatus J. Ag. — Fig. 7. 



I. Agardh, Nya alger fran Mexico (Ofversigt af K. Vetensk.-Akad. Forhandl., 

 1847, P- 7)- Borgesen, F., Marine Algae of the D. W. I, vol. I, p. 173. — Ecto- 

 carpus hamatus Cr. in Maze et Schramm, Essai de classification des algues de la 

 Guadeloupe, 2 e Edit. 1870 — 77, p. 111; Vickers, A., Phycologia Barbadensis, part 



I I, pi. 2Q. 



The specimens found quite agree with the West Indian plant. 



The filaments are about 30 ;j. thick. The length of the cells is rather 

 variable. Near the summit of the filaments and generally in the periphery of 

 the tufts the cells mostly are about as long as broad, while in the main fila- 

 ments in the interior of the tufts the cells are often more than twice as long 

 as broad. 



1 Skottsberg, C, Bot. Ergebnisse d. sclnved. Exp. nach Patagonien und <iem Feuerlande. 

 VIII. Marine Algae. 1. Phaeophyceae, p. 9. 



