36 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



cross walls, and in not having granules collected at the cross 

 walls. 



Oscillatoria Willei sp. nov. 



Plate 7, figure 67 



Plants forming an indefinite stratum; tricliomes pale aerugi- 

 nous, flexuose, uncinate to semi-spiral at the apices, blunt, 2.4- 

 2.6 M diam. ; cells quadrate to 2 times as long, homogeneous, walls 

 inconspicuous, not constricted ; terminal cell blunt, rounded, not 

 thickened. 



Growing among water plants in a reservoir at the Experi- 

 ment Station, Kio Piedras, no. 169, type, and 192 a ; in a water 

 fall in a brook of warm water, Coamo Springs, no. 369, and in a 

 ditch at that sj^ring, Coamo Springs, no. 391 a. 



Oscillatoria Willei is closely related structurally to 0. laete- 

 virens Crouan. It differs from that species in being smaller, in 

 not being constricted at the cross walls, in not being acute at the 

 apices, and in not being granular. The apices are at times 

 almost spiral. 



Oscii.LATORiA CHALYBEA insularis var. nov. 

 Plate 7, figure 68 



Trichomes straight except at the slightly unicinate apices, 

 and relatively rigid, 6.4-7.2 n diam., not constricted ; cells quad- 

 rate or less than the diameter long, otherwise as the species. 



Collected by Dr. W. C. Earle in the vicinity of Manati, Porto 

 Rico, growing on aquatic plants and free-floating. 



Oscillatoria chlorina conica var. nov. 

 Plate 7, figure 69 



Trichomes long, arcuate, 3.4-3.6 m diam. ; cells quadrate to 

 one-half longer than the diam. ; cross-walls obscure ; apical cell 

 conical. 



Collected by Dr. W. C. Iilarle in the vicinity of Manati, Porto 

 Rico, growing on aquatic plants and free-floating. 



Oscillatoria Earlei sp. nov. 



Plate 8, figure 70 



Trichomes very small in diam. and short, straight except at 

 the sharply attenuated and uncinate ends, 2.2-2.4 n diam., not 



