CHROOLEPUS. 121 



These forms have not a proper place here ; they are intro- 

 duced merely as illustrations of the pseudo-genus, Gongrosira, 

 and as aids to the novice. 



Genus 22, CHKOOLEPUS, Ag. 



Filaments irregularly branched, often so closely interwoven 

 that the branches are scarcely discernible. Stems and primary 

 branches of the same thickness ; cell contents of a reddish 

 brown, golden yellow, or olive color, sometimes with a tendency 

 to green ; zoospores about thirty -two in a cell, also of reddish 

 brown or golden yellow color, provided with two ciliae. These 

 little motile bodies are produced in certain cells set apart for the 

 purpose, usually on the end of a filament, sometimes on the 

 side, seldom in the middle of a filament ; when these cells are 

 sufficiently matured the endochrome breaks up into minute parts, 

 the future zoospores. Wille, of Sweden, made these bodies a 

 special study and found that- they copulate freely. After a mo- 

 tile life of a few hours they grow sluggish, sink in water, divide, 

 and soon commence to form new filaments. 



Plate CXV, figs. 18, 19, represent the individual zoo- 

 spores (under higher power than figs. 16, 17), then the first 

 stage of copulation ; next, the cells uniting more closely and 

 finally the two running together form a perfect sphere 

 with one head and four ciliae ; figs. 20, 21, similar progressive 

 stages. 



CHROOLEPUS AUREUS, (Linn. ) Kg. 



Golden red or orange ; threads either collected in small 

 tufts, or spreading in a soft silky stratum; sometimes in- 

 tricately and densely matted and expanded ; very much 

 branched. Cells as long, or two or three times longer, than 

 the diameter. 



Diameter of cells, 10-12 //. 

 Diameter zoosporangia, about 20 yw. 



Syn. Conferva aurea, Dillw. ; Byssus aurea, Eng. Bot. ; Ceramium 

 aureum, Hook ; TrentepoJilia aurea, Ag. 

 Affects moist places, walls, rocks, old wood, etc. 



Plate CXV, figs. 1-4, filaments of fruiting plants : figs. 5, 

 6, 7, another form ; figs. 8-15, zoosporangia ; figs. 16, 21, 

 zoospores escaping from the sporangia; figs. 18-21, zoo- 

 spores, some swarming singly, others in first stages of copu- 

 lation ; others, spherical, united, completely fertilized. 



