216 University of California Publications in Botany [Vol. 8 



9. Cladophora laetevirens (Dilhv.) Kuetz. 



Plants 15-20 cm. high, erect, rigid, bright yellow green; filaments 

 much branched, flexuous, 50-150/a diam. ; branches erect, often oppo- 

 site; ultimate ramuli short (usually 1-3 segments), obtuse or subacute, 

 densely- fastigiate at the tips of the branches; segments of main 

 branches 6 diameters long, of ramuli 3 diameters. 



Kuetzing, Phyc. Gen., 1843, p. 263; Harvey, Phyc. Brit., vol. 2, 

 1849, pi. 190 ; Notice of a collection of algae, etc., 1862, p. 177 ; Setchell 

 and Gardner, Alg. N.W. Amer., 1903, p. 224; Collins, Green Alg. 

 N. A., 1909, p. 345. Conferva laetevirens, Dillwyn, Brit. Conf., 1805, 

 pi. 48. 



The only reason for including this species bej'ond the record of 

 Harvey (1862a, p. 177) for Fuca Strait, apparently based on two small 

 and young specimens, is the collection of what seem to be characteristic 

 specimens by Butler and Policy near Port Renfrew, B. C. These 

 have been carefully compared with no. 143 of Wyatt's Algae Dan- 

 monienses both by F. S. Collins and by ourselves and they seem to be 

 in close agreement with it. 



10. Cladophora gracilis (Griff.) Kuetz. 



Plants moderately rigid, forming somewhat slender, pyramidal 

 fascicles, 15-30 cm. high, pale or glaucous green, di- trichotomous at 

 the base; main filaments up to 160/a diam., segments 4—7 times as long 

 as the diameter ; main branches smaller and beset with numerous 

 slender, tapering, secund ramuli constricted at the joints. 



Growing on rocks in shallow tide pools, in the upper and middle 

 littoral belts. Sitka, Alaska, and Neah Bay, near Cape Flattery, 

 Washington. 



Kuetzing, Phyc. Germ., 1845, p. 215; Collins, Green Alg. N. A., 

 1909, p. 342. Cladophora vadorum Kuetzing, Sp. Alg., 1849, p. 402, 

 Tab. Phyc, vol. 4, 1854, p. 4, pi. 20, f. I. Conferva gracilis Griffiths, 

 in Wyatt, Alg. Danm., no. 97. 



The limits of Cladophora gracilis have not been clearly defined. 

 Either it is an exceedingly variable species, or several closely related 

 species have been grouped into one by different authors. Kuetzing 

 (1845, p. 215) gives 113-124^^, De-Toni (1889, p. 322) gives 100-140^^, 

 and Collins (1909, p. 342) gives up to 160/ji as the diameter of the 

 main filaments of this species. Collins {loc. cit., p. 343) has recognized 



