1925] Setchell-Gardner: Melanophyceae 533 



The occurrence or non-occurrence of hairs is such a variable char- 

 acter as is also the presence or absence of the ' ' unicellular paraphyses ' ' 

 (possibly hypertrophied gametangia ?) in all of our variants of the 

 species that we have not found it possible to use either structure in 

 any of them as a diagnostic character of much significance. 



1. Scytosiphon Lomentaria f. typicus S. and G. 



Plate 39, fig. 45, and plate 44, fig. 75 



Plants of the largest size of the genus, both as to length and 

 diameter, dark brown to olive green in color, more or less regularly 

 and deeply constricted; paraphyses ( ?) cylindrical to slightly clavate, 

 not projecting beyond the gametangia, with chromatophores often 

 collected at the outer end ; gametangia with 10-15 loculi. 



Growing on rocks in pools in the lower littoral belt. Port Clarence, 

 Alaska, to southern California. 



Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 323&; 

 Tilden, Amer. Alg. (Exsicc), no. 246. 



2. Scytosiphon Lomentaria f. cylindricus major 



Fronds from 6-25 cm, long. 1,5-2.5 mm. diam., not constricted, 

 cylindrical, long-attenuated at both ends, light brown in color. 



Growing on rocks in the lower littoral or in tide pools in the upper 

 littoral belts. Central California. 



Collins, Holden and Setchell, Phyc. Bor.-Amer, (Exsicc), no. 

 1389. Chordaria attenuata Tilden, Amer. Alg. (Exsicc), nos. 347a, 

 3476 ? 



The cylindrical unconstricted forms seem to be fairly well estab- 

 lished both as regards habitat and form. They grow in tide pools, 

 often even above high-tide level, and the size seems to be materially 

 influenced by the size and depth of such pools. In these pools where 

 they are frequently to be found, they are generally far removed from 

 the typical form which grows usually in deep tide pools in the middle 

 and lower littoral belts. 



3. Scytosiphon Lomentaria f. cylindricus minor 



Fronds less than 6 cm. high, 1-1.5 mm. diam., cylindrical, uncon- 

 stricted. 



Growing on rocks along high-tide line in localities exposed to wave 

 action. Central California (San Francisco). 



