EXPLANATIONS AND REFERENCES, 

 PLATE CXXV. 



Figures magnified 125 diameters. 



PAGE. 



Fig. 1-0. SCHIZOMERIS LEIBLEINII, parts of filaments. The vegetative 



plant and broken ends with zoogo- 

 nidia passing out . . See below. 



Figs. 7, 8. Young plants, ..... 



Fig. 9. ENTEROMOKPHA INTESTINALIS . . . (308), 107 



" 10. ENTEROMORPHA, small portion of membrane of older plant 



highly magnified, . . . .107 



" 11. CHAETOMORPHA, natural size, . . . 148 



" 12-13. Sections of filaments enlarued, . . . . .144 



" 14. Escaping microgonidia, ..... 144 



[A description of the following genus was inadvertently omitted in the 

 proper place, (page 17),]. 



Genus, SCHIZOMERIS, Kg. 



Thallus chlorophyl green, filiform, composed primarily of a 

 single series of cells which are usually broader than long, here 

 and there strongly contracted ; at first attached by a disc-like 

 expansion of a narrow base, later often floating in mass ; grows 

 in the beginning by the division of the cells transversely, later 

 in two or three directions. 



Zoogonidia are formed in the cells of younger plants; they 

 escape singly from the thinner filaments and in larger numbers 

 from the larger ones ; they are furnished with two or three cilia. 



SCHIZOMERIS LEIBLEINII, Kg. 



Bright green to deep blackish-green. 

 Diameter of filaments, 20-125 /*. 



'Frequent in ditches and ponds, Pennsylvania, New Jer- 

 sey, Florida, and probably in every State. 



It is easily recognized by a Ulothrix-\ike look, which soon 

 becomes familiar to the eye; it is larger than most of the 

 species of Ulothrix, more irregular in outline by constric- 

 tions, the basal parts thin and the apices usually tapering to 

 a point ; the fruiting is also distinct. 



