NEW MYXOPHYCEA.E FROM POKTO RICO 



3 



Synechococcus intermedius sp. nov. 



PlATK 1, FIGUKE 3 



Cells I'ree, not aggregated into a stratum, narrowly eyliiidri- 

 cal, ()-7 M diam., 12-14 [i long, bright aeruginons, homogeneous, 

 very thin-walled. 



Growing on the bark of trees, Caguas, no. 439 b, type; on old 

 leaves in a stream west of Humacao, nos. 581 a and 602 ; east of 

 Humacao, no. 640 ; on bark near Guanica, no. 1841 c. 



Dactylococcopsis arcuata sp. nov. 



Plate 1, figure 4 



Cells 45-55 \\ long, 1.4-1.8 n diam., gently arcuate, free ; Avail 

 very thin, contents homogeneous, yellowish green. 



Growing among other Myxoijhyceae on the bark of a tree 

 trunk, Caguas, no. 439 e, type. 



The si^ecimens of this species are very sparse, but seem un- 

 mistakably to be distinct, and apparently closely related to D. 

 acicularis Lemmerm., from which it differs in being shorter, nar- 

 roAver, curved, and free from refringent granules. 



Chroothece Willei sp. nov. 



Plate 1, figure 5 



Cells cylindrical, straight or more or less curved, Avith 

 rounded ends, pale aeruginous to slightly yelloAvish, Avithout 

 tegument 5.8-6.2 m diam., 18-22 n long ; tegument 8-10 m thick, 

 hyaline, homogeneous. 



GroAving in small clusters among other Myxophyceae, on 

 limestone, Hato Arriba, Arecibo, no. 1410, type. 



This is a very distinct species Avith relatively long and nar- 

 row cells, many of Avhich are more or less curved. Unfortu- 

 nately, the material is not abundant, as shown by its sparsity in 

 the previously mentioned collection, the only one in Avhich it Avas 

 found. 



Merismopedia Willei sp. nov. 



Plate 1, figure 6 



Families composed of 256-560 cells ; membrane more or less 

 distorted, 6.5-7.5 m thick ; cells subcylindrical in surface A^iew just 

 preA'ious to cell division, 4.5-6 n by 7.6 p, nearly spherical in 

 resting condition. 



