1919J Setchcll-GarchKr: Myxophyceae 61 



Growing on mud in salt marshes and floating in pools of salt 

 water. Puget Sound, Washington, to central California. 



Crouan, in Desmazieres, PI. cr.Ypt. de France, 2 ser., no. 537, 1858 

 (fide Gomont) ; Gomont, Monogr. des Oscill., 1892, p. 215, pi. 6, figs. 

 17, 18 (1893, p. 235, Repr.) ; Setchell and Gardner, Alg. N.W. Auier., 

 1903, p. 183 (small form) ; Collins, Ilolden, and Setchell, Phyc. Bor.- 

 Amer. (Exsicc), no. 1707. 



According to Gomont {loc. cit.) this species has a considerable 

 variation in diameter, viz., from 18/i to 36/a, although not so great as 

 that given for 0. princeps, which is IQjx to QO/x (Gomont, 1892, p. 207). 

 In general, no single collection shows any such variation in the 

 diameter of the filaments and it seems possible that there may be 

 necessity- for more careful study of these seemingly polymorphous 

 species. What seems to be good 0. Bonnemaisonii has occurred at 

 Whidbey Island, Washington (cf. Setchell and Gardner, 1903, p. 183) 

 and about San Francisco Bay, California (cf. Ph^'c. Bor.-Amer., nos. 

 1707a., h, and d). 



3. Oscillatoria margaritifera (Kuetz.) Gomont 



Trichomes bright olive green, forming dark agglomerated masses, 

 or intermixed with other algae, very flexible, torulose, 17-29)U, diam., 

 straight, arcuate at the ends and slightly attenuate, obtuse; length 

 of cells 3-6/a; apical cell capitate, furnished with a slightly convex 

 calyptra ; protoplasm with numerous large granules distributed along 

 the crass walls. 



Growing on mud and in pools in salt marshes. San Francisco Bay, 

 California. 



Gomont, Monogr. des Oscill., 1892, p. 161, pi. 6, fig. 19 (1893, 

 p. 236, Repr.) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 1708. Oscillaria margaritifera Kuetzing, Tab. Phyc, 

 vol. 1, 1846, p. 31, pi. 43, fig. 10. 



What seems to be this species has been encountered several times 

 in tlie salt marshes about San Francisco Bay, California. The calyp- 

 trate tip is well shown in our specimens. 



Under no. 1604 in Phycotheca Boreali-Americana this species is 

 said to occur in the specimen distributed. We fail to find it in the 

 specimens in our copies, there having been some confusion and mis- 

 takes of identification as already indicated above under 0. ornnta. 



