44 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



homo^i^eneoiis, caerulescent to slightly drab-colored ; apical cell 

 blunt-conical; cross-walls very distinct; sheath hyaline, very 

 thin, but distinct, not confluent. 



Growing on red earth, Maricao, no 1056, type. 



Phormidium calcicola sp. nov. 



Plate 9, figure 87 



Filaments forming a thick, tough stratum, densely encrusted 

 with calcium carbonate, tortuous and intricately intertwined, 

 7-8 M diam. ; trichomes 5.8-6.4 \i diam., not constricted ; apices 

 not attenuated ; cells quadrate, varying to slightly longer or 

 shorter, contents homogeneous, pale aeruginous; cross-walls 

 thin; end walls distinctly thickened, apical cell blunt, rounded; 

 sheath thin, homogeneous, hyaline. 



Growing in a waterfall, between Arecibo and Utuado, no. 

 1460, type. 



The habit character of this species of Plionnidium is very 

 pronounced. 



Phormidium interruptum rigidum var. nov. 



Filaments considerably tortuous, rigid; trichome 4.8-5.2 |j 

 diam., not constricted ; cells up to 2 times as long as broad ; end 

 cell rounded and end wall very slightly thickened, color very pale 

 purplish-olive; sheath relatively thick, smooth, firm, hyaline to 

 dark brown at maturity. 



Growing on bark of trees, Coamo Springs, no. 300 e, type ; 

 and on the wall of a church, Sabana Grande, no. 952; on rocks 

 near Coamo Springs, no. 358 a. 



The variety rigidum differs from the species in having longer 

 cells and a firm, rigid, brown sheath. 



Phormidium interruptum capitatum var. nov. 



Trichomes 6.5-7.4 n diam. ; cells quadrate or longer ; terminal 

 cell rounded, capitate, otherwise as the species. 



Growing in the vicinity of Humacao, mo. 540, type. 



The variety capitatum differs from the species only in the 

 characters mentioned in the diagnosis. The trichomes are 

 larger; the cells longer, and the end cell, at maturity, has a 

 thickened terminal wall. 



