30 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



gelatinous on the surface ; cells spherical, 2-2.4 m diam., usually 

 api^earing in groups of 2 or 4 on the surface of the colony ; co- 

 lonial tegument more or less hyaline ; individual cells and groups 

 of 2-4 enclosed in special teguments more or less deeply colored 

 violet or purplish. 



Growing at "Campo" north of Maricao, no. 1290 c, type col- 

 lected by Dr. N. L. Britton ; oji bark, Utuado, no. 1506 c ; on rocks, 

 near Laguna Joyuda, Mayagiiez, no. 1209. 



Entophysalis chlorophora sp. nov. 



Plate 6, figure 55 



Plants forming a more or less continuous stratum 50-100 \x 

 thick on the surface of smooth pebbles, firm and cartilaginous ; 

 cells 2-2.5 M diam., angular, arranged more or less in rows per- 

 pendicular to the substratum, forming somewhat false-branched 

 filaments embedded within the common tegument, greenish aeru- 

 ginous. 



Growing on pebbles in a stream of warm water by Hot 

 Springs, Coamo Springs, no. 381, type. 



Entophysalis violacea sp. nov. 



Plate 6, figure 56 



Plants forming microscopic cushions 60-80 m thick on rock, 

 subcartilaginous ; cells 1.5-2.5 \x diam., spherical to radially elon- 

 gated, arranged in radial, more or less false-branched filaments 

 perpendicular to the substratum ; cells embedded more or less in 

 individual teguments all agglutinated into a common tegument 

 opalescent on the interior of the colony, violet on the surface. 



Growing on rocks at llato Arriba, Arecibo, no. 1433, type. 



CYANOTHRIX gen. nov. 



Plants filamentous, cylindrical, monosiphonous, composed of 

 a single series of cells generated by fission in one plane and 

 held together by an ample gelatinous tegument. Type species, 

 Cyanothrix primaria. 



In creating this genus it is unfortunate that the material 

 upon which it is based is not more abundant in the collections 

 than I have been able to locate. The plants are very sparsely 

 scattered among other algae and debris. Thus it has been im- 



