SCHlZOSPOREvE. 235 



Genus SO, CBATEBOSBEBMUM, A. Br. 



Filamentous, elongated, membrane thin. Chi arophyl -green 

 cell contents primarily diffused, later more contracted into an 

 axillary band. Copulation geniculate. Zygospore spherical, in- 

 volved in a cylindrico-subquadrangular membrane, at the point 

 of conjugation. 



CRATEROSPERMUM LAETEVIRENS, A. Br. 



Diameter of vegetative filaments, 38 /* ; cells 3-8 times 

 longer than broad ; zygospores green, changing to oliva- 

 ceous, or brown. Floating in rather light green interwoven 

 masses. 



Syn. Mougeotia craterosperma, Itz. 



The only specimens recognized as possibly of this genus, 

 were collected, July, 1880, in Green Bond, New Jersey. The 

 conjugation was complete, but the spores were imperfectly 

 developed, hence my hesitancy in calling it a pronounced 

 species of this genus. 



Blate CL, figs. 11, 12, the conjugated cells as observed. 



Class III. CYANOPHYCE^E. 



(BHYCOCHROMOPHYCE^E. ) 



Blants one or many-celled, living in water, or enclosed in a 

 maternal jelly when out of it, mostly in families formed from 

 successive generations of cells. Cell membrane (cytioderm} not 

 siliceous, combustible. Cell contents (cytioplasm] variously col- 

 ored by means of phycochrome, aeruginous, red, violet, orange 

 yellow, brown, or olivaceous, but never chlorophyl-green ; desti- 

 tute of nucleus and usually without starch granules. 



Order YL SCHIZOSPORE^E. 



(CYSTIPHOR^:. ) 



Cells single or united in single or branched series ; they divide 

 in one direction only. Cytioderm soft, smooth, immersed in a 

 more or less liquid or firm mucilage, variable in color, for the 

 most part irregularly disposed. 



The two families NOSTOCACE^: and CHROOCOCCACEJE are sep- 

 arated by the former having the cells united after division into 

 filamentous series, and the latter having the cells separated and 

 scattered. 



