NEW MYXOPHYCEAE FROM PORTO RICO 



9 



Growing in a water basin west of the Experiment Station, 

 Rio Piedras, no. 1965, type. 



This species of Chroococcus is to be distinguished from 

 others by the deep constrictions which appear between the cells 

 during and after division of the protoplast, frequently com- 

 pletely separating the two resulting cells before the second divi- 

 sion appears. 



Chroococcus heanogloios sp. nov. 



Plate 2, figure 20 



Cells homogeneous, olive-green, aggregated into small groups 

 on the filaments of the host, associated into colonies of 2-4, 

 spherical when existing singly, 8-10 jj diam., compressed and 

 angular in colonies of 2 or 4; colonies of 4 with tegument 18-20 n 

 diam. ; tegument hyaline, homogeneous, thin and apparently 

 membranaceous but glutinous. 



Growing more or less ejoiphytic on Scytonema capitatum on 

 rocks about ten kilometers north of Utuado, no. 1537 c, type. 



The unusual epiphytic habit, and the very thin, somewhat 

 gelatinous tegument are characters distinguishing this species of 

 Chroococcus. 



Gloeocapsa cartilaginea sp. nov. 



Plate 2, figure 21 



Families adhering by their gelatinous walls forming a homo- 

 geneous, tough, cartilaginous stratum 2-2.3 mm. thick; cells 

 spherical, jDale aeruginous, 1.5-2.5 \i diam., forming families of 

 2-4, rarely more ; families of four, 6-8 m diam. ; common tegu- 

 ments hyaline, cartilaginous, homogeneous ; teguments of indi- 

 vidual cells and small families soon becoming confluent, not 

 lamellose. 



Growing on red soil near Maricao, no. 1025, type. 



Gloeocapsa cartilaginea minor var. nov. 



Families of four 7.5-9.5 m diam., cells 0.8-1.2 (j diam., forming 

 stratum 2-3 mm. thick, individual teguments very distinct and 

 opalescent, otherwise as the species. 



Growing on limestone between Hatillo and Arecibo, no. 1377, 

 type; near Hato Arriba, Arecibo, no. 1428. 



