4 26 



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 to a form. 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. 



Pig. i.Ulvella lens, after Crouan (1859). A, Section of Fig. n.Gomontia polyrhiza, after Lagerheim (1883). A 

 thallus; B, Surface view. Vegetative cell; B, Aplanosporangium. 



Pig. >. A, Chatomorpha linum f. aerea; B, Ctuetomorpha Fig. s- Udotea cyathiformis, X78, after Howe (1909). Apices 

 brachygona; C, Chatomorpha melagonium I. rupincola. X47. of cortical filaments of stipe. 



Fig. 3. Rkizoclonium riparium. A, X47; B, Xa8i. Fig. 6. Udoiea conglutinata, X 78, after Howe (1909). Apices 



of cortical filaments of stipe. 



3. Chaetomorpha brachygona Harvey. Fig. zB. 



Chcetomorpha brachygona, Harvey, 1858, p. 87. pi. 463. 

 Ctuetomorpha brachygona, De Toni, 1889, p. 267. 

 Ch&tomorpha 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 

 algae; 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 algae 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. 



