^^20] Setchdl-Gardncr : Chlorophyce'ae 201 



Kuetzing, Sp. Alg., 1849, p. 379; Collins, Green Alg. N. A., 1909, 

 p. 324; Collins, Holden and Setehell, Phyc. Bor.-Amer. (Exsicc), 

 no. 76. Conferva aerea Dillwj-n, Brit. Conf., 1809, pi. 80. 



We feel rea.sonably safe in referring certain specimens from the 

 central and southern coasts of California to this widespread species 

 after carefully comparing them with specimens from the European 

 and New England coasts. Our plants favor shallow rock pools, more 

 or less lined with sand and situated higii up in the littoral belt where 

 the water is wanned by the sun. The specimens available for exam- 

 ination are rather young and range from 200/i, to 300/* above. Tlie 

 filaments are erect and tufted, and collapse on being taken from tiie 

 water. The plants are grass green below but lighter and yellowish 

 above, the color dying away at the tips. This species does not seem 

 to form entangled masses above and we have found no specimens 

 corresponding to the Chaetomorpha. Linum of the New England coasts 

 and those of Europe, which is supposed to be a state or variety of 

 C. aerea. AVe do not find plants over 30()/x in diameter in any of our 

 specimens, whether in those from our own coasts or those from New 

 England or Europe. This is less than the extreme measurements given 

 by some writers (e.g., 600-700/i, for zoosporangia bj^ De-Toni, 1889, 

 p. 273) but agrees well with those given by Farlow (1881, p. 46) for 

 tlic New England plant. The basal segment is short, never ranging, 

 in specimens examined, over 1.5 mm. in length. The upper segments 

 in specimens approaching maturity are short, usually from 0.5 to 

 once as long as broad, but the lower segments may be as much as twice 

 longer than broad. The segments in fertile condition, or approaching 

 it, are slightly swollen and short barrel-shaped. 



3. Chaetomorpha melagonium (Wei), and ]\Iohr) Kuetz. 



Filaments closeh' cespitose or, at times, scattered, attached by short, 

 stout rhizoids coalescing with those of adjacent plants, erect, coarse, 

 stiff, dark glaucous green, 2-6 dm. long, 300-700/* diam. ; segments 

 1-2 diameters long, basal segments slightly attenuated below, up to 

 2.5-2.75 mm. long. 



Unalaska and Kadiak Island, Alaska. 



Kuetzing, Pliyc. Germ., 1845, p. 204; Collins, Green Alg. N. A., 

 1909, p. 323; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 222. 

 Conferva mela-ganiuni Web. and Mohr, Reise nach Schweden, 1804, 

 p. 194, pi. 3, f. 2; Harvey, Phyc. Brit., 1846, vol. 1, pi. 99; Ruprecht, 

 Tange, 1851, p. 396. 



