60 MEMOIRS OF THE NEW YOKK BOTANICAL GARDEN 



mately quadrate, pale aeruginous to slightly purplish in mass ; 

 apical cells blunt, rounded, sometimes smaller than others; 

 heterocysts spherical to subspherical, 5.2-6 m diam. ; spores 

 spherical to slightly longer in part, wall hyaline or somewhat 

 discolored at maturity, smooth, seriate, or discontinuous, de- 

 veloping toward the heterocysts, 5-6.4 n diam., 6-7.5 n long. 



Aggregated into small masses or free ; among other algae in 

 a stream about five kilometers east of Coamo, no. 235 h, type. 



Two other species of Anabaena were found associated with 

 this one, both, however, sterile, and I have not classified them. 



Anabaena Willei sp. nov. 



Plate 12, p'iguke 10 



Trichomes bright aeruginous, long, relatively straight, deeply 

 constricted at the dissepiments, 4.8-5.2 \\ diam., attenuated at 

 the apices ; cells short, mostly quadrate, cylindrical, finely gran- 

 ular; apical cell conical; heterocysts cylindrical or somewhat 

 dolioform, 5-6 \y diam., 9-12 \\ long, hyaline ; spores cylindrical, 

 6.5-8.6 M diam., 15-20 p long, smooth, outer layer slightly brown 

 in color, densely granular, bright blue-green, 2-3-catenate next 

 to the heterocysts. 



Growing in a pool among other algae, Jayuya, no. 1750, type ; 

 in a ditch. Ponce, no. 1670 «; in a small stream about five kilo- 

 meters east of Coamo, no. 237. 



Anabaena Willei belongs to the Sphaerozyga section of the 

 genus, as limited by Agardh (Aufzaehlung, 634, 1827) and is 

 related to A. oscillarioides. 



Anabaena aeruginosa sp. nov. 



Plate 12, figure 11 



Trichomes relatively short and straight, aggregated into 

 small masses or free-floating, 3.2-4 m diam., not attenuated ; cells 

 l)right aeruginous, subspherical, seemingly loosely attached to 

 each other ; apical cell blunt-rounded ; heterocysts lil<;e the cells 

 in form, 5-6 m diam. ; spores ])roadly dolioform, 2-4-catenate be- 

 tween the heterocysts, about 10 p diam. and 15 m long, contents 

 densely and coarsely granular, bright aeruginous, walls smooth, 

 hyaline. 



Growing in company with Anahacna Willei and other algae 

 about five kilometers east of Coamo, no. 237 h, type. 



This species of Anabaena belongs in the Dolichospermum sec- 

 tion of the group, proposed by Ealfs (Nostoch. 325, 1850) but 



