MARINE ALG OF BEAUFORT, N. C. 425 
The material from Beaufort is finer and less rigid than most specimens of this species from other 
localities, approaching in this respect C. linum, but is coarser and more rigid than most specimens of the 
latter species. The comparative width of the filaments is as follows: C. melagoniwm, 180 to 440 mic.; 
C. linum, 142 to 434 mic.; C. melagonium (Beaufort specimens), 120 to 240 mic. Both of the former 
have length of cells from slightly less than x to more than 2 diameters, the Beaufort specimens have 
length of cells from two-thirds to 2 diameters, the majority of cells being 1 diameter or less. In spite 
of these variations, there seems little doubt that the material from Beaufort belongs to this species, 
forma rupincola. It is easily distinguished from C. linwm at Beaufort by its coarse, rigid, dark-green 
filaments. 
It has been found at this place only in May, 1907, not being observed in April, 1908. This is a 
northern species, and the present locality is the most southern station reported for it. It is not improb- 
able that this is its southern limit, although it may be found farther south in the winter or spring. 
2. Cheetomorpha linum (Mueller) Kuetzing. 
Conferva linum, Mueller, in Flora Danica, tom. s, p. 4, pl. 771, f. 2, 1782. 
Chetomor pha linum, Kuetzing, 1845a, p. 204. 
Chetomorpha sutoria, Harvey, 1858, p. 87. 
Chetomorpha longiarticulata, Harvey, 1858, p. 86, pl. 46, E. 
Chetomor pha olneyi, Harvey, 1858, p. 86, pl. 46, D. 
Chatomorpha linum, Farlow, 1882, p. 47- 
Chetomor pha linum, De Toni, 1889, p. 269. 
Chetomorpha aerea f. linum, Collins, 1909, p. 325. 
Cheetomor pha linum, Collins, 1918, D. 79. 
A. A. B. Ex. No. 175. 
P. B.-A. Nos. 22, 1863 (C. aerea f. linum). 
Filaments unattached, prostrate, light green, rather stiff, diameter 200 to 250 mic., cells about as 
long as broad. 
Nova Scotia to West Indies; warm and temperate waters generally. 
Rather rare, shoal south of laboratory, Beaufort, N. C., August, 1903 (?); marsh west of laboratory, 
August, 1907 (?). 
This species apparently bears the same relation to C. linum f. aerea as the loose form of C. melagonium 
does to the attached form. It occurs in great masses of curled and crisped filaments in warm, shallow 
bays. 
The Beaufort material probably belongs to this species, but was not found in sufficient quantity for 
a positive determination. 
Forma aerea (Dillwyn) Collins. Fig. 2A. 
Conferva aerea, Dillwyn, 1809, pl. 80. 
Chetomorpka aerea, Kuetzing, 18494, p. 379. 
Chatomorphka aerea, Harvey, 1858, p. 86. 
Chatomorpha aerea, Farlow, 1882, p. 46. 
Chetomor pha aerea, De Toni, 1889, p. 272. 
Chatomorpha aerea, Collins, 1909, p. 324, pl. 12, f. rr5. 
Chetomor pha linum £. aerea, Collins, 1918, D. 79. 
P. B.-A. Nos. 76, 1526 (C. aerea). 
Filaments attached, erect, yellowish green, 125 to 400 mic. or less in diameter, cells about as long as 
broad, base of filament usually more slender than the upper part; when producing zoospores the fertile 
cells are much inflated and nearly globular. 
Maine to West Indies; California; warm and temperate waters generally. 
Sometimes abundant on rocks between jetties at Fort Macon, summer and autumn, forming flaccid, 
tangled masses of filaments about 6 dm. above low water, and fairly abundant on sea buoy, September, 
1905, Beaufort, N.C. Abundant on rocks in tide pool, Morris Island, ro cm. above to ro cm. below 
water level, water warm to touch, Charleston, S. C. 
In habit like C. melagonium, but of somewhat smaller diameter, lighter color and softer texture; 
not firm enough to stand erect when taken from the water. 
Of varying degrees of coarseness. The Beaufort material is finer than specimens from other locali- 
ties, being 80 to 110 mic. wide, with cells go to 225 mic. long. In characters other than the size of the 
filaments, this material seems to agree with ‘‘C. aerea,’’ as observed in herbaria, and is certainly more 
