NEW MYXOPHYCEAE FROM PORTO RICO 



1)1 



Stigonema minutum ramentaceum var. nov. 



Filaments 300^00 m (up to 600 n) long, profusely beset with 

 short, blunt, horniogoniferous ramuli on all sides; main fila- 

 ments about 2') [\ (liam. 



Growing on old wood at Laguna Tortuguero, no. 848, type. 



Stigonema ramosissimum sp. nov. 



Plate 21, figure 54 



Fronds about 500 n high, profusely branched, more or less 

 arborescent, all of the parts crooked and about equal in diam- 

 eter, blunt, 25-30 n diam. ; cells 4-6-seriate, without definite ar- 

 rangement, the zones being more or less disarranged by sec- 

 ondary, horizontal cell division, spherical to subspherical, or 

 irregular in shape and size, closely crowding the thin, yellowish 

 brown, homogeneous wall, producing a somewhat tuberculate 

 appearance, 7-10 n diam. ; individual cells or groups of cells en- 

 closed in a distinct tegument at maturity; hormogoniferous 

 branches numerous, short, arising on all sides and terminating 

 most of the branches. 



Growing on rocks at Laguna Tortuguero, no. 852 c, type ; on 

 old palm trunks at Hacienda, Laguna Tortuguero, no. 870; on 

 red earth at Maricao, no. 1025 a. 



Stigonema spiniferum sp. nov. 



Plate 22, figure 56 



Filaments 500-700 n long, 35-45 n (up to 60 p) diam., very 

 irregularly and profusely branched, no distinction into main 

 fronds and branches ; all branches more or less attenuated and 

 terminating in more or less curved, spine-like, hormogOnial por- 

 tions ; cells multiseriate in part but usually 4-seriate, in distinct 

 nodular clusters, when numerous subspherical, usually the lon- 

 gitudinal diameter longer than the cross diameter, olive-green, 

 homogeneous ; sheath 10-15 n thick, hyaline, homogeneous, in age 

 the teguments of the individual cells and groups of cells yellow- 

 ish ; the hormogoniferous apical portions, or branches, thick, 

 white, attenuated to a very sharp point, 60-90 \i long ; hormo- 

 gonia usually clavate and uniseriate, larger at the outer end, 

 escaping by rupture of the outer end of the spine; heterocysts 

 sparse and inconspicuous. 



Growing on soil at "Campo," Maricao, no. 1229, type. 



