1920] Setchell-Gardner: Chlorophyccae 185 



3. Rhizoclonium Kerneri Stock. 



Filaments pale yellowish green, segments 10-14ju. diam., 3-7 diam- 

 eters long, free from rliizoids or branches. 



Growing in loose masses in tide-pools. Victoria, Vancouver Island, 

 British Columbia. 



Stockmayer, Ueber die Algengat. Rhizoclonium, 1890, p. 582; 

 Collins, Mar. Alg. Vancouver Island, 1913, p. 103, 



We have not seen any specimens of this species and are including 

 it upon the authority of Collins {loc. cit.). It is decidedly more slen- 

 der than tlic other four species of BhizocJoniuiit thus far detected on 

 our coast. 



4. Rhizoclonium lubricum S. and G. 

 Plate 9, figs. 5«, h 



Filaments flaccid, lubricous, straight, eylindrieai throughout, 3- 

 4.5 dm. long, pale green ; segments 35-50/1,, mostl}" 40/a diam., resting 

 segments 4-6 diam. long, after division segments 1-2 diam. long; 

 chromatophore a coarse, parietal network ; pj^renoids small, numerous, 

 40-50 in resting segments; wall 2ju, thick, homogeneous; rhizoids short, 

 mere prolongations of cells, non-septate, rare ; zoospores and gametes 

 unknown. 



Growing attached in mud or floating on mud flats between tides. 

 Roche Harbor, Washington, and Berkeley and Alameda on the shores 

 of San Francisco Bay, California. 



Setchell and Gardner, in Gardner, New Pac. Coast Mar. Alg. IV, 

 1919, p. 492, pi. 42, f. 5; Collins, Holden and Setchell, Pliyc. Bor.- 

 Amer. (Exsicc), no. 2289. 



This form closely resembles R. riparium f. validum Fo^lie, but is 

 practically free from rhizoids, has thinner walls and larger and longer 

 segments. P^rom R. implexum it diff'ers in having broader, straigliter 

 filaments of very diff'erent consistency, as well as, usually', longer seg- 

 ments. Unlike other species of Rhizoclonium it is very lubricous, in 

 mass, having the consistency of a Spirogyra. 



5. Rhizoclonium tortuosum (Dillw.) Kuetz. 



Filaments rigid, crispate and contorted, dark green, 40-70/i, diam., 

 forming woolly skeinlike or ropelike horizontal masses; segments 1-2, 

 up to 6 times as long as broad, wall thick, indistinctly lamellose ; 

 rhizoids short, few or, more usually, none. 



