MARINE ALGA! OF BEAUFORT, N. C. 439 
lateral, not opposite, often arcuately ascending; filaments 40 to 60 mic. in diameter; cells about 1 diameter 
long in the upper portion of the frond, often 4 to 5 diameters long below, somewhat constricted at the 
septa; sporangia of both kinds usually on the same individual; ‘‘unilocular sporangia’’ 30 to 65 
(usually 50) mic, by 20 to 27 mic., ovoid or ellipsoid, sessile, or pedicillate; ‘‘ plurilocular sporangia’”’ 
50 to 600 (usually 200) mic. by 12 to 25 mic., conical-subulate, rarely short ovate, sometimes slightly 
arcuate, often tapering to a hair; the products of the “plurilocular sporangia’ are morphologically 
similar gametes; according to present views, the female gamete finally ceases its locomotion and 
usually fuses with an actively motile male gamete; the gametes of either sex may germinate without 
copulation. 
Cold and temperate North Atlantic; Alaska; Mediterranean. 
Beaufort, N. C.—Abundant throughout harbor, 5 to 15 cm. below low water, and on Bogue Beach, 
April, 1908; very abundant throughout harbor and on Fort Macon jetties, May, 1907. 
This species is distinguished with difficulty from E. confervoides, with which it is often confused. 
It differs from the latter in the greater diameter of its branches and its usually more tapering “ pluri- 
locular sporangia.’’ The sporangia of these two species seem, however, tointergrade. The illustration 
(fig. 8) shows about the average shape of the sporangia observed in E. siliculosus by the author. Some 
of these are very long and extended into a long, slender, pointed hair, while some are shorter, approaching 
closely to the more slender sporangia of E. confervoides. 
3. Ectocarpus confervoides (Roth) Le Jolis. Fig. 9. 
Ceramium confervoides, Roth, 1797, p. 151. 
Ectocarpus confervoides, Le Jolis, 1863, p. 75. 
Ectocarpus confervoides, Farlow, 1882, p. 71. 
Ectocarpus confervoides, De Toni, 1895, Dp. 551- 
P. B.-A. No. 871. 
Fronds 2 to 50cm. long, attached, deep brown; branches scattered, secund or alternate, not opposite; 
lower cells of the branches 18 to 40 mic. in diameter; ‘‘ unilocular sporangia’ oval or ellipsoidal, 23 to 30 
mic. broad, 35 to 50 mic. long, sessile; “‘plurilocular sporangia’’ short subulate or fusoid, sessile or 
shortly pedicellate, 20 to 4o mic. broad, 60 to 4oo mic. long, not tapering to a hair. 
Cold and temperate North Atlantic and Pacific; Mediterranean. 
Common in harbor and on rocks of Fort Macon jetties, Beaufort, N. C., January to April, 1909. 
This species is distinguished with difficulty from E. siliclulosus, with which it is often confused. 
From this it differs in the smaller diameter of its branches and its less tapering ‘‘ plurilocular sporangia.”’ 
Authors have distinguished several varieties or forms, some perhaps agreeing in all respects with forms 
of E. siliculosus. 
4. Ectocarpus mitchelle Harvey. Fig. 1o. 
Ectocarpus mitchelle, Harvey, 1852, p. 142, pl. 12 G. 
Ectocarpus mitchelle, Farlow, 1882, p. 72- 
Ectocarpus mitchelle, De Toni, 189s, p. 558. 
P. B.-A. Nos. 321, 671, 1921. 
Fronds 1.5 to 17cm. long, yellow-greenish to dark brown, forming lax, feathery tufts; filaments 
slender, profusely branched; branches and branchlets alternate, ultimate ones approximate, all patent; 
cells of the branches 2 to 3 diameters long, those of the branchlets r.5 diameters; “ plurilocular sporangia” 
elliptical oblong or linear, very obtuse, sessile, divided into numerous cells, several together. 
Warm and temperate North Atlantic and Pacific. 
Abundant on other alge, marine grasses, shells, ete.,on shoals throughout harbor, on buoys, and 
on rocks of Fort Macon jetties, Beaufort, N. C., summer and autumn; Bogue Beach, March, 1909. 
Very abundant on marine grasses and rocks on shoals and jetties, Pamlico Sound, Ocracoke, N. C., 
August, 1907. Fruits throughout summer and autumn. 
With the exception of E. duchassaingianus, collected in a single locality, this is the only deter- 
minable species of Ectocarpus that has been found at Beaufort in the summer and autumn. 
A small amount of Ectocarpus evidently belonging to another species than those 
described here (fig. 11), but insufficient for specific determination, was dredged from the 
coral reef offshore from Beaufort in August, 1914. 
