82 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



young is hyaline and homogeneous, and the filaments relatively 

 short, permanent characters of S. subgelatinosum. At maturity 

 the branching is very profuse near the outer ends of the fila- 

 ments, the sheath becomes brownish, laminated, and in part 

 ocreate, characters which do not appear in S. subgelatinosum. 



Hassalia brevis sp. nov. 



Plate 18, figure 40 



Filaments 100-130 p long, 8.5-10.5 \i diam., densely matted 

 together forming a thin, pannose stratum; mostly straight or 

 arcuate in part; trichome frequently separated at the hetero- 

 cyst, forming numerous short filaments ; cells 7.2-8.4 n diam., 

 dolioform, about one-half the diameter long; heterocysts numer- 

 ous, compressed-spherical, golden-colored ; sheath very thin, 

 smooth and hyaline ; branches short, 50-70 p long. 



Growing on a concrete fountain in Fajardo, no. 659, type ; on 

 trees, Coamo Springs, no. 300 c ; on old wood at Hacienda Cata- 

 lina. Palmer, no. 747; Laguna Tortuguero, no. 864; on loose rock 

 about seven kilometers east of Coamo, nos. 1869 h and 1870 f. 



Practically all of the material at hand of this species of Has- 

 salia is in the hormogonial stage, the filaments having separated 

 at the heterocysts by the decay of the delicate sheath at that 

 point. There are a few branches intact, however, that show 

 clearly the rupture of the sheath and the filament emerging just 

 below the heterocyst. The sheath decomposes at a very large 

 i:)ercentage of the heterocysts, whether branches arise there or 

 not, leaving the whole mass of filaments broken, and the hetero- 

 cysts all basal on the trichomes. 



Hassalia granulata sp. nov. 

 Plate 18, figure 41 



Filaments 100-200 \x long, 11-13.5 n diam., straight or some- 

 what arcuate, forming a very thin, more or less flocculent stra- 

 tum; trichomes 10-12 p diam., pale aeruginous, very slightly 

 constricted at the dissepiments, of uniform diameter throughout 

 the entire length ; cells one-third to one-fourth the diameter long, 

 densely congested with granules, often collected along the very 

 inconspicuous cross-walls; heterocysts suliglobose to much com- 

 pressed, golden yellow, mostly terminal, brought about by rui> 



