1919] Setchell-Gardncr : MyxopJiyceae ' 11 



Growing in fn sh and in brackish water along high-tide line, Alaska 

 to central California. 



Naegeli, Gatt. eiuz. Alg., 1849, p. 46; Setchell and Gardner, Alg. 

 N.W. Amer., 1903, p. 179. Protococcxs turgidufi Knetzing. Tab. Phyc, 

 vol. 1, 1846, p. 5, pi. 6, fig. 1. 



The type of the species is to be found in Herb. Kuetzing and shows 

 the plant to bo mingled with fragments of a moss and consequently 

 as occurring in fresh water. Tiie type locality is not given with 

 definiteness but is stated in the Species algarum (1849a, p. 198) to be 

 Germany. Single cells of the type are about 8/a in diameter, but with 

 the teguments are 12-16/a in diameter. The teguments show distinct 

 stratification and colonies of eight cells, of total diameter of 40/^, are 

 frequent. Altogether the type specimens correspond exactly to 

 Kuetzing 's figures and description. 



Chroococcus turgidus is not properly a marine species but an 

 inhabitant of fresh water. The forms occurring in the brackish water 

 of pools of the salt marshes and just above high water mark are larger, 

 with variable color of the protoplast. Most, if not all of them, are 

 more properly to be referred to the following variety. 



Chroococcus turgidus f. submarinus Ilansg. 



Plate 1, fig. 14 



Single cell spherical, protoplast 22-26/x diam., tegument 5-6/a 

 thick; two-celled colony 40^5/* diam., 50-60/x long, cells angular; 

 extremely variable in color in the same collection. 



Growing on CJiaetomorpha calif ornica Collins, in rock pools along 

 high-tide line, at present credited to a single locality, Laguna Beach, 

 Orange County, California, but probably extending along the entire 

 coast in suitable habitat. 



Hansgirg, Beitriige Kennt. Meeresalgen, 1889, p. 6 ; Collins, llolden 

 and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 1551. 



Although a single locality is quoted, it seeras probable that the 

 forma submarinus really includes all the specimens found in strictly 

 brackish water. 



5. Placoma Schousb. 



Colonies spherical or lobed, solid or hollow, with cells arranged 

 more or less radially, at least toward the surface, and quaternate ; 

 tegument of colony structureless, special teguments of cells more or 

 less stratified as in Gloeocapsa; division in three planes. 



