MARINE ALG OF BEAUFORT, N. C. 419 
Thirty species, usually in salt or brackish water, occasionally in fresh water, through- 
out the world. 
The specific distinctions are founded chiefly on the manner of branching and on the 
size and arrangement of the cells and are often difficult of determination. 
KEY TO SPECIES. 
a. Frond flat, the membranes free at the margins, but united between............. 4. E. linza (p. 420). 
ag.) Frond tubbtalases 0c ti eos Sek oe chan delineate LAR) RTE, RARE EIS b. 
6. Cells not arranged in longitudinal series except in the very youngest parts.. 
A aictateverers inys aletals) slelareteiaisiarerersiaietele’s aielayv yaaa delet ewido ofa Ree ete te. 3: E. aasaes (p. 420). 
bb. Cells more or less in longitudinal series, usually in the greater part of the frond............... c. 
e. Pronds'simple; inflated) and) AEXuU0US 2c. cep re n= seteielelaie* slope cia an ae 2. E. flexuosa (p. 419). 
ce. Bronds! resularly* bran ched.0e sate Sestseean fe chete ee inlels tye voisdeters eee abe cleha a 1. E. prolifera (p. 419). 
1. Enteromorpha prolifera (Flora Danica) J. Agardh. 
Ulva prolifera, Flora Danica, vol. 5, fasc. 14, p. 7, pl. 763, fig. 1, 1832. 
Enteromorpha prolifera, J. Agardh, 1882, p. 129, pl. 4, figs. 103-104. 
Enteromorpha prolifera, De Toni, 1889, p. 122. 
Enteromorpha prolifera, Collins, 1909, p. 202. 
P. B.-A. Nos. 470, 610, 913. 
Frond up to several meters long and 2 cm, in diameter, tubular or compressed, with more or less 
abundant branches which are usually simple, but sometimes also proliferous; branches varying much in 
length and diameter; cells 10 to 12 mic., in the younger parts always arranged in longitudinal series, 
which become less distinct in the older parts; membrane 15 to 18 mic. thick, not much exceeding the 
dimensions of the cells in cross section. 
Greenland to West Indies; Alaska to California; Europe. 
Beaufort, N. C.: Abundant throughout winter 1908-1909; very abundant May, 1907, and April, 
1908, on rocks, shells, and piers throughout harbor and at Fort Macon and Shackleford, extending from 
about 10 cm. below low water to high-water line; very abundant at water line on sea buoy and channel 
buoy at entrance to Beaufort Harbor, July, 1909; abundant on rocks and sand breaks at Shackleford and 
Fort Macon between tide lines throughout summer (?). Cape Lookout beach, very abundant on old 
wreck about 20 m. from water at low tide, August, 1906. Pamlico Sound, Ocracoke, N. C., fairly 
abundant on posts of beacon between tide lines (?). Southport, N. C., very abundant on wall and 
shore, August, 1909. Georgetown, S. C., very abundant on jetty and shellson beach. Pawleys Island, 
near Georgetown, S. C., abundant on shells in bay near inlet. Port Royal, S. C., fairly abundant on 
buoy at water line. 
This seems to be the only species of Enteromorpha occurring in this region throughout the year. 
Specimens collected in December are 3 to 4 cm. long, densely matted with many upright, filiform or 
club-shaped branches; in April and May this species is, next to Ulva lactuca, the most abundant in the 
harbor; the specimens at this time are 3 to 45 cm. long; in summer, material apparently belonging to this 
species is found as small, stunted tufts, 1 to 2 cm. long, on rocks and sand breaks near the inlet, this condi- 
tion continuing as late as October or November. With the exception of these stunted representatives 
and of specimens occasionally growing on buoys, etc., this species has not been found here during the 
summer or autumn. 
In habit this species is very variable, from slender, slightly branched forms, only a few centimeters 
long, to rich and repeatedly branched fronds; delicate or coarse; branches sometimes long and slender, 
sometimes short and very densely set, sometimes long and short intermingled quite without order. It 
also occurs in fresh water and about salt springs. 
2. Enteromorpha flexuosa (Wulfen) J. Agardh. 
Conferva flexuosa, Wulfen, in Roth, 1800, p. 188. 
Enteromorpha flexuosa, J. Agardh, 1882, p. 126. 
Enteromor pha flexuosa, De Toni, 1889, p. 121. 
Enteromorpha flexuosa, Collins, 1909, p. 203. 
P. B.-A. Nos. 462, 2004. 
Frond cylindrical, tubular, simple, tapering to a filiform stipe below, above inflated, flexuous, and 
intestinelike; cells 6 to 8 by 8 to 12 mic., roundish polygonal, in longitudinal series; membrane somewhat 
thickened on the inside; chromatophore filling the thick-walled cell. 
