NEW MYXOPHYCEAK FROM POKTO lUCO 



61 



has straight spores instead of curved ones, characteristic of 

 most of the species of the section. Its closest affinity seems to 

 be A. ohlonga De Wilden. 



Anabaena epiphytica sp. nuv. 



Trichomes epiphytic, firmly attached, few at first, mostly 

 parallel and contiguous, extending lengthwise of the host, later 

 comi)letely surrounding it and in places becoming more than 

 one layer deep, brought about by secondary growth of inter- 

 calary cells ; cells subspherical, 5-5.3 m diam., usually less than 

 the diameter in length ; heterocysts spherical or compressed- 

 spherical, 6-6.3 n diam. ; spores unknown. 



Growing on other filamentous algae in a pool near the Ex- 

 periment Station, Rio Piedras, no. 1947, type, no. 154 h, and no. 

 1946 a. 



Unfortunately the complete life history of this species of 

 Anabaena cannot be given at this time, the material having no 

 resting spores. The size and structure of the trichomes, com- 

 bined with the -habitat (growing firmly attached to other plants, 

 e.g., Oedogonium in the case of no. 1947) seem to warrant giving 

 the material specific rank. 



Anabaena delicatissima sp. nov. 



PlATK 12, FIGURE 12 



Trichomes short, straight, free-floating, tegument inconspicu- 

 ous, transparent, 2.3-2.5 \x diam., deeply constricted at the dis- 

 sepiments ; apices blunt ; cells compressed-spherical, about two- 

 thirds as long as the diameter; heterocysts spherical, slightly 

 larger than the cells ; spores unknown. 



Floating or attached to water-inhabiting plants among nu- 

 nerous other species of Myxophyceae. Collected by Dr. W. C. 

 Earle in the vicinity of Manati, Porto Eico, in 1925. 



Although it is not generally advisable to identify species of 

 Anabaena Avithout spores, the very small size of the vegetative 

 parts of the above species makes it appear to be wholly distinct 

 from any known species of the genus. 



Anabaena mediocris sp. nov. 



Plate 12, figure 13 



Trichomes relatively straight; cells cylindrical to slightly 

 dolioform, deeply constricted, 4-4.5 n diam., 1-2 times as long 



