1919] Setchell-Gardner : Myxophyceue 63 



Oscillaforia Corallinae resembles the other members of the same 

 section of OsciUatorm, but it is smaHer tliaii any except the last, from 

 which it differs by not liaving granular dissepiments. Its general 

 appearance is tiiat of a very small 0. Bonnemaisoiiii, but it is much 

 smaller than even the most slender forms referred to that species. 

 It is usuall}', if not always, epiphj-tic. 



Section 3. Aequales Gomont 



Trichomes not attenuate above, straight or arcuate ; cells at least 

 one-third as long as broad up to equally long; slender species of not 

 over llfx. in diameter ; largely fresh water. 



Gomont, Monogr. des OscilL, 1892, p. 202 (1893, p. 222, Repr.). 



6. 0. amphihia Ag. 



7. 0. geminata Menegh. 



6. Oscillatoria amphibia Ag. 



Trichomes forming a thin layer at the bottom of quiet water or 

 floating on the surface, color pale copper acetate, straight or some- 

 what contorted in age, fragile, not constricted at the partitions, 2-3/i, 

 diam. ; terminal cells not attenuate nor capitate, with outer cell wall 

 rounded ; cells 2-3 times as long as the diameter, up to 8/x long ; proto- 

 plast homogeneous except with usually 2 granules at the dissepiments 

 wliieh are obscure. 



Growing in pools in salt marshes, usually in company with other 

 species of Oscillatoria. Puget Sound, Washington and San Francisco 

 Bay, California. 



Agardh, Aufziihlung, in Flora, vol. 10, 1827, p. 632; Gomont, 

 Monogr. des OscilL, 1892, p. 221, pi. 7, figs. 4, 5 (1893, p. 241, Repr.). 



Judging from the figures of Gomont {loc. citJ), Oscillatoria, am- 

 phihi-a does not show dissepiments until the protoplasts are dissolved 

 out with strong acids. What seems to be this species, although in 

 some cases var3ang slightly from it, has occurred to us in salt marshes. 

 The species usuallj^ occurs in few or isolated filaments intermixed with 

 other homocysted forms. 



7. Oscillatoria geminata ]\Ienegh. 



Trichomes pale aeruginous color, matted together into a tliin, 

 sordid, j'ellowish green stratum, occasionally circinate, slightly fragile, 

 constricted ratlier deeply at the dissepiments, 2..3-4/X diam., 2.3-1 6/x 



