122 FRESH-WATER ALG^ OF THE UNITED STATES. 



Var. CORTICULUM, Wolle. 



In size and form very near the typical plant, not golden 

 yellow, but yellowish green with a seeming tendency to yel- 

 low ; on the bark of trees, sometimes in firm mats of 3-4 

 inches in extent. 



Trees, Southern Florida. 



Plate CXV, figs. 18-21 ; figs. 22-25, sporangial cells, var. 

 corticulum. 



CHROOLEPUS IOLITHUS, (Linn.) Ag. 



Stratum thin, scarcely 2 mm thick, glaucous or dirty 

 greenish when dry, sometimes reddish orange; threads and 

 branches elongated, rather dichotomous, variously curved, 

 ascending ; cells 13-3 times as long as their diameter ; in the 

 upper portion of the branches reaching double that length. 



Diameter filaments, 25-40 IJL. 

 Diameter zoosporangia, 50 yw. 



Syn. Byssus lolithm. Linn. ; Olivia violacea, Gray ; TrentepohUa 

 lolithus, Wallr. ; also familiarly known on the Alps as 

 Veilchenmoos and Vettchenstein, the stones overgrown with 

 it, emitting, particularly when moistened, a strong 

 fragrance, of violets. 

 Moist rocks, White Mountains, N. H. 



CHROOLEPUS ODORATUS, (Lyngb.) Ag. 



Stratum thin, rather tonientose, rufous-tawny ; when dry 

 cinereous, becoming greenish. Filaments and branches 

 short, erect, parallel, flexuously curved, torulose ; cells 

 equal or twice as long as broad. 



Diameter of filaments, 9-14 /.i. 



Have copied this diagnosis from Rabenhorst's Flora Al- 

 f/anun. It does not describe the plants figured in all details ; 

 they appear to be young plants, not fully developed. They 

 occur on the bark of shade trees along the highways. 



Syn. Conferva odorata, Lyngb. 

 Plate CXVI, fig. 6. 



CHROOLEPUS LICHENICOLUS, Ag. 



Stratum reddish orange ; filaments short and thin, greg- 

 arious, often confluent ; when dry, of light yellow color ; 

 branches variously and flexuously curved. Diameter of 

 filaments 7-9 /* ; articulations 1-3 times longer ; cylindrical 



