NEW MYXOPHYCEAE FROM PORTO RlOO 



65 



Nodularia Willei sp. nov. 



Plate 12, ficiuke 15 



Filaments 9-10.5 m diam,, straight, short ; trichomes 8.4-8.8 m 

 diam. ; cells disk-shaped or very much compressed spheres ; 3.8- 

 4.5 M long, contents finely granular, aeruginous ; heterocysts sub- 

 spherical to compressed-spherical, slightly larger than the cells, 

 with hyaline walls changing to jiale amber; spores seriate be- 

 tween the heterocysts, 9.5-10 n diam. densely granular, walls 

 hyaline, changing to brown at maturity, very thin and smooth; 

 sheath almost transparent, soft gelatinous. 



Growing in a pool near Laguna Guanica, no. 1817 a, type. 



Nodularia epiphytica sp. nov. 



Plate 12, figure 16 



Filaments aggregated into small masses or scattered more or 

 less upon the host ; mostly relatively straight but in part curved, 

 60-125 M long, 4.7-5 \\ diam. ; trichomes 3-3.8 \x diam. ; cells bright 

 aeruginous, ho-mogeneous, in part showing a clear central area, 

 about one-half the diameter long, deeply constricted at dissepi- 

 ments, making them short-dolioform; apical cell subspherical ; 

 heterocysts of the same shape and size as the cells, or in part 

 larger, sparse, at times 2-3-seriate ; sheath very nearly trans- 

 parent, thin; spores unknown. 



Growing on a very small species of Hepaticae on limestone, 

 Hato Arriba, Arecibo, no. 1415 a, type; Coamo Springs, no. 

 282 d. 



It is unfortunate that the material is not producing resting 

 spores so that the Avhole life history might be given of this very 

 diminutive, though distinct, species of Nodularia. It apparently 

 is closely related to A^. Harveyana (Thwaites) Thuret, but has 

 much shorter cells. 



Leptochaete tenella sp. nov. 



Plate 12, figure 17 



Filaments erect, closely crowded together, 80-150 m long, 1.5- 

 2.2 |j at the base, tapering very gradually toward the apex, form- 

 ing a very thin continuous stratum ; trichomes 1-1.4 |j diam. at 

 the base, tapering to an exceedingly narrow hair above ; cells 

 quadrate or less ; gonidia free at the base, mostly uniseriate. 



