272 FRESH-WATER ALG^E OF THE UNITED STATES. 



The plant was found on damp soil, not on trees, collected 

 by Dr. Hosford, of Charlotte, Vermont. The sheath is col- 

 orless, the trichomes light blue, about one-third as wide as 

 the sheath. The macrogonidia were seen escaping at the 

 broken ends of the rather short filaments. 



Plate CXCII, figs. 3-5, filaments ; fig. 6, macrogonidia. 



SlROSIPHON OCELLATUS, Kg. 



Stratum more or less expanded, woolly-tonientose, dark 

 olive brown ; filaments elongate, irregularly branched ; 

 branches, primary and secondary ; cells of the stems mostly 

 biseriate, and of the branches commonly uniseriate, subglo- 

 bose or oblong compressed, equal or one-half, or one-third as 

 long as broad, normally aeruginous ; sheaths thick, often 

 laniellose, golden brown, external layers now and then paler ; 

 sheaths of the branches colorless, or yellowish, quite smooth. 



Diameter of filaments, 12-38 ^. 



Syn. Stigonema ocellatum, Thur. ; Hassallia ocellata, Hass. ; Con- 

 ferva ocellata, Dillw. ; Scytonema ocellatum, Harv. ; Sirosi- 

 phon pellucidulus, Wood. 



Most frequent in small pools, swamps; also in larger 

 ponds. The finest specimens occurred in Bamber Lake, 

 New Jersey, attached to submerged sticks in dark brown 

 waving tufts about one-half inch in length. Samples of this 

 are preserved in Wittrock and Nordstedt's Algce Exsiccatae, 

 No. 668, A.D. 1883. 



Plate CXCIV, figs. 1-3, three fragments of branching fila- 

 ments ; fig. 4, part of a broken filament ; fig. 5, the rnicro- 

 gonidia bearing cells ; fig. 6, the same, sliding out of the 

 sheath and developing ; figs. 7-10, young plants. 



SIROSIPHON CRAMERI, Bruegg. 



Forming a blackish, widely expanded, tornentose, turfy 

 covering to rocks ; filaments with scattered branches ; 

 branches mostly single, often elongate and clavate ; cells 

 uniseriate about equal or shorter than long, sometimes sub- 

 globose; in advanced age often strongly compressed and 

 transversely oblong from mutual pressure, yellowish, or 

 sometimes when young, greenish ; the apical cells coalescent 

 into an irregularly cylindrical mass, (merely a condition of 

 young growth, ) sheaths yellowish brown ; at maturity more 

 or less opaque and distinctly lamellate ; in youth more or 

 less transparent, and sometimes colorless. 



