1919] Setchcll-Gardner : Myxophyceae 69 



1. Phormidiiim fragile (Menegh.) Gomont 



Filaments forming a thin A'clluwish or dark blue-green stratum, at 

 times lamellate ; trichomes more or less fiexuous, bright blue-green, 

 moniliform, 1.2-2. 3/Lt diam. ; apices attenuate, acute conical, without 

 calyptra ; protoplasm homogeneous. 



San Francisco Ba}-, California. 



Gomont, Monogr. des Oscill., 1892, p. 163, pi. 4, figs. 13-15 

 (1893, p. 183, Repr.) ; Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 1609. Anabaena fragilis Menegliini, Conspectus Algol. 

 Eugan., 1837, p. 8. 



Tlie t^'pe locality for this species is the thermal water of the 

 Euganean springs, but, as seemingly often happens, the species 

 reappears in shallow brackish waters. The specimens referred here 

 agree with the description of Gomont so far as aggregation and 

 diameter and torulosity of the trichome are concerned, but the 

 trichomes are not so attenuate as that represented on plate 4, figure 

 14, but fully as much so as that represented by figure 15. It agrees 

 also with a specimen from Kiel collected by Reinbold and determined 

 by Gomont. 



2. Phormidium hormoides S. and G. 

 Plate 6, fig. 23 



Filaments forming a thin, expanded, gelatinous stratum ; tri- 

 chomes short, somewhat fiexuous, moniliform, 2.4— 2.7/i, diam. ; sheaths 

 hyaline, ample gelatinous, confluent ; cells quadrate or subquadrate, 

 extremely constricted at the dissepiments, terminal cell larger, sub- 

 spherical, end wall not thickened. 



Forming a thin layer on glass aquaria of salt water from the 

 Pacific Ocean. Physiological Laboratory, University of California, 

 Berkeley, California, 1905. 



Setchell and Gardner, in Gardner, New Pac. Coast Alg. Ill, 1918rt, 

 p. 467, pi. 40, fig. 23. 



Phormidium hormoides is very closelj^ related to Ph. foveolarum 

 (Mont.) Gomont, which was found growing in small pits in calcareous 

 rock on the coast of France, and from which it differs in habitat, in 

 the size of the filament and in the shape of the terminal cell. The 

 filaments as viewed under the microscope are not uniformly dis- 

 tributed in the stratum but seem to have a tendency to aggregate into 

 fascicles which anastomose freely, giving the stratum somewhat the 



