NEW MYXOPHYCEAE FROM PORTO RICO 



5 



Aphanothece opalescens sp. nov. 



Pl;ATE 1, FICVKE S 



Colonies irregular in outline, more or less nodular, subgelati- 

 nous, up to 200 n diam. ; cells 1-1.4 n diam., 2-2.4 times as long 

 as the diam., yellowish green; colonial tegument opalescent, 

 moderately firm, ample, the individual teguments around each 

 cell or small group of cells remaining distinct and visible for 

 some time, giving to the colony the appearance of a pile of fused 

 spheres ; the individual sheaths ample, not lamellose. 



Growing intermixed with other species of Myxophyceae, at 

 La Chiquita near Maricao, no. 1144 e, type, collected by Dr. N. 

 L. Britton. 



Aphanothece bacilloidea sp. nov. 

 Plate 1, figure 10 



Cells aggregated into microscopic masses, indefinite in shape 

 and size, not forming a definite stratum, short, cylindrical, 0.8- 

 1 \x diam., about 2 times as long as the diameter. 



Growing in depressions in limestone at Hato Arriba, Arecibo, 

 no. 1407 a, type ; in depressions in limestone between Hatillo and 

 Arecibo, no. 1378 ; among other Myxophyceae in an underground 

 passage in Fort San Cristobal, San Juan, no. 1989 c. 



Aphanothece conferta brevis var. nov. 



Cells 3.5 n diam., 4.5-5 \i long, when in rapid division sub- 

 spherical, otherAvise as the species. 



Growing on a water pipe by a stream, near Maricao, no. 1147, 

 type; on rocks between Utuado and Adjuntas, no. 1635 a. 



Aphanothece microscopica granulosa var. nov. 

 Plate 1, figure 11 



Colonies irregular in outline at maturity, up to 400 \\ diam. ; 

 cells 4.5-5 |j diam., 7-8 \i long, densely granular, yellowish or 

 honey-colored ; tegument yelloAvish brown. 



Growing on rocks at Penuelas, no. 1848 a, type. 



Chroococcus cubicus sp. nov. 



Plate 1, figure 12 



Cells associated into families of 2-4, free among other algae, 

 not forming a stratum alone ; single cells with tegument 1.8-2.5 \i 

 diam., spherical to somewhat irregular in outline, very pale 



