76 



MEMOIRS OF THE KEW YORK BOTANICAL GARDEN 



Growing on rocks between Utuado and Adjuntas, no. 1658, 

 type. 



The species above described may be distinguished from other 

 known species by the relatively large diameter of the trichomes, 

 not diminishing appreciably in the older parts, the bright aeru- 

 ginous cylindrical cells which are usually very finely granular, 

 and the hyaline, finely punctate sheath, esi^ecially so in the older 

 filaments. 



ScYTONEMA MiLLERi majus var. nov. 



P'ilaments forming small tufts or a continuous stratum about 

 4 mm. thick, densely packed together, erect, very flexuous, 20- 

 25 M diam. ; cells slightly dolioform at the apices of the trichomes, 

 cylindrical in tlie older parts, one-half to one-third the diameter 

 long at the apices, mostly quadrate in the older parts ; branching 

 and heterocysts sparse ; sheath thick, firm, dark brown, homo- 

 geneous. 



Growing on rocks by a stream near Maricao, no. 1166, type. 



The measurements given by Forti^'^ for the filaments of 8. 

 Milleri are 15-21 |j in diameter. The material distributed in the 

 copy of Wittrock, Nordstedt and Lagerheim, Alg. Exsic, no. 

 1511, at the Farlow Herbarium, Harvard University, determined 

 by P'^lahault, measures 12-15 m in diameter. The material de- 

 scribed above resembles no. 1511 {loc. cit.) very much, but is 

 larger in all of its parts. It is close to some forms of S. guy- 

 anense, but has a firm, homogeneous sheath, and the material is 

 thoroughly mature. 



Scytonema pulchellum sp. noY. 



Plate 16, figure 33 



Filaments 10-15 \\ diam., moderately straight, long, arcuate, 

 rigid, entangled into a flocculent stratum about 2 mm. thick, 

 sparsely branched, either single under the heterocysts or gemi- 

 nate between the heterocysts; tricliomes very distinct, variable 

 in diam., largest in the meristematic regions, diminishing in the 

 older parts; 5-10 m diam., not constricted at the dissepiments; 

 cells cylindrical, 2-3.5 times as long as the diameter in older 

 parts of the trichome, quadrate to one-half as long at the apices ; 

 pale olive-green, homogeneous or with one to several refringent 



15 In De Toni, Sylloge Algarum 5: 505. 1907. 



