1917] Gardner: New Pacific Coast Marin.e Algae I 385 



p. 222) has retained the two genera separate, however, stating that 

 it is diffieult to establish distinctions among Gayella, Schizogonium 

 and Prasiola. 



I have had Gayella constricta under observation for over eighteen 

 months, having the material of it and the accompanying Prasiola 

 growing in the laboratory for over eight months. In some areas on 

 the rocks the two plants are intermingled, but in others they are 

 entirely separate, and the two can be distinguished by size and color, 

 the Prasiola being larger and the Gayella much deeper green. There 

 has not yet appeared the slightest indications of a metamorphosis of 

 one into the other, though many new plants have started. The evi- 

 dence thus far at hand is that these two forms should be kept as 

 distinct genera. 



I have compared Gayella constricta with the material of Gayella 

 polyrhiza Kosenvinge, as distributed in Collins, Holden and Setchell, 

 Phycotheca Boreali-Americana, no. 914. This distribution, though 

 to a large degree comparatively young, seems to be quite typical, 

 agreeing verj' closely with the descriptions and figures by Rosenvinge 

 (1893, pp. 936-939). It possesses abundance of rhizoids, which in 

 this instance are mere prolongations of single cells remaining undi- 

 vided. G. constricta differs from G. polyrhiza in having fewer 

 rhizoids and these usually much longer and multicellular; in having 

 deep constrictions in the mature filaments caused by failure of certain 

 cells to divide vertically; and in tlie filaments being uncinate. 



Myelophycus intestinalis f. tenuis Setchell et Gardner forma nov. 



Caespitosus, inconspicue tortus, 1.5-2.5 cm. altus, 0.25-0.75 mm. 

 diam. ; sporangiis unilocularibus late ellipticis, 40^5/i. longis, 30-35/1, 

 latis ; singulis aliis ut in specie. 



Plants caespitose, inconspicuously twisted, 1.5-2.5 cm. high, .25- 

 .75 mm. diam. ; unilocular sporangia broadly elliptical, 40-45/x long, 

 30-35/x wide ; otherwise as the species. 



Growing on rocks, usually in sheltered localities at high tide level 

 or even above, wliere the spray daslies. Common on tlie central Cali- 

 fornia coast, and known as far north as Coos Bay, Oi'egon. Tlie type 

 locality is Fort Point, San Francisco, California. 



This form differs from the species chiefly in size and in habitat. 

 When the coast between Coos Bay and Puget Sound is more tlior- 

 oughh' investigated forma tmuis will doubtless be found growing 

 lower and lower down in tlie littoral belt as well as becoming larger 

 and larger northward, merging into the Puget Sound form. 



