ULOTHRIX 151 
Hormiscia oscillarina DeToni, Syll. Alg. 1: 167. 1889. 
Cells about 11 £ in diameter, and ۲-1 as long, or equal to 
the diameter in length ; senkt a broad band. 
Exsic.: Phyc. Bor. Am. 673, Melrose, Mass., Aug. 1890, 
floating in a ditch (F. S. Collins). 
When we visited this station in May, Igor, with Mr. Collins, no 
Ulothrix was to be seen; possibly this is unlike most species of 
this genus in being a summer form. 
A specimen labelled U. osci//ariua from Wisconsin in the 
Wolle herbarium is 777001761718 sp. 
In regard to the name of this species, it is probable that 
Agardh’s form ought to be used. The specimen issued as Con- 
ferva oscillatorioides Ag. (Desmaz. Pl. Crypt. de France, 7353) 
agrees closely with Mr. Collins’ plant; but as we have no means 
of determining with certainty the character of Agardh’s plant, 
Kützing’s name is here retained, as being the one in current use. 
5. ULOTHRIX TENERRIMA (Kütz.) Kütz. Phyc. Gen. 253. ۸۰ 9. f. 7. 
1843; Phyc. Germ. 197. 1845; Spec. Alg. 346. 1849 
(Exel, var): Tab. Phyc. 2: W. 87: f. r. 1892. Rabenb. 
Krypt. Flor. Sachs. 1: 264. 1863; Flor. Eur. Alg. 3: 366. 
1868. Gay, Rech. sur Ale Vert. ۸. 12. f. 119. 1891. 
Conferva tenerrima Kütz. Linnaea, 8: 346, 347, 361. f. ۰ 
1833. 
Myxonema ۶ tenerrimum Rabenh. Deutsch. Krypt. Flor. 2?: 
99. 
Ulothrix subtilis tenerrima Kirchner, Krypt. Flor. Schles. 
2!: 77. 1878. Wolle, F. W. Alg. 136. ۸. 226. f. 17. 1887. 
Hormiscia subtilis tenerrima DeToni, Syll. Ale 1: 160. 1889. 
Ulothrix tenuis Kitz. Spec. Alg. 346. 1849. (?) 
Filaments forming light green silky or floccose masses often 1 
dm. long ; cells cylindrical, 7.5-9 مم‎ in diameter, 24-1 14 times as 
long ; cell-wall very thin; chromatophore zonate or conico to 
one side of the cell, with one pyrenoid ) .لمر‎ 27. f. 3, 4) 
On the sides of an iron fountain basin, and in a wooden water- 
ing-trough, St. Johnsbury, Vermont, September and October 
(645, 651). 
The chromatophore in the actively vegetative state is zonate, 
and the appearance of a filament is then like a miniature specimen 
