426 BULLETIN OF THE BUREAU OF FISHERIES. 
like that species than like any of the others recorded from North America. This is the finest of the 
three representatives of this genus occurring at Beaufort. 
It seems somewhat irrational to consider a floating plant as the species and to refer the more natural, 
attached plant toaform. As was pointed out by Howe (1914, p. 99) this procedure is, however, required 
by the rules of botanical nomenclature, since C. linum was described before C. aerea and must, conse- 
quently, take precedence over the latter form. 
5 4 
Fig. 1.—Ulvella lens, after Crouan (1859). A, Section of Fig. 4.—Gomontia polyrhiza, after Lagerheim (1885). A 
thalius; B, Surface view. Vegetative cell; B, Aplanosporangium. 
Fig. 2.—A, Chaetomorpha linum {. aerea; B, Chatomorpha Fig. s.—Udotea cyathiformis, X78, after Howe (1909). Apices 
brachygona; C, Chetomorpha melagonium f{. rupincola. X47. of cortical filaments of stipe. 
Fig. 3.—Rhizoclonium riparium. A, X47; B, X28r. Fig. 6.—Udotea conglutinata, X78, after Howe (1909). Apices 
of cortical filaments of stipe. 
3. Chetomorpha brachygona Harvey. Fig. 2B. 
Chatomor pha brachygona, Harvey, 1858, p. 87, pl. 46a. 
Chetomor pha brachygona, De Toni, 1889, p. 267. 
Chatomor pha brachygona, Collins, 1909, p. 325- 
P. B.-A. No. 622. 
Filaments free, rigid, curved, and twisted, forming strata of some extent on rocks or among other 
alge; cells 125 to 175 mic. diameter, quite uniformly as long as broad, except just after dividing. 
Florida; West Indies; Mexico. 
Rather abundant, mixed with other algz floating in harbor, Beaufort, N. C., September and Octo- 
ber, 1905; large, tangled mass Bogue Beach, September, 1906. 
The material from Beaufort Harbor has the diameter of filaments 100 to 175 mic. This species, as it 
occurs there, is intermediate in appearance between C. melagonium and C. linum f. aerea, being finer, 
less rigid, and lighter green than the former, and coarser, more rigid, and darker green than the latter. 
This is the most northern station reported for the species, and is probably its northern limit. 
