150 ULOTHRICACEAE 
to be younger forms of U. sonata. In the two stations above 
quoted, however, we have never been able to find typical speci- 
mens of U. sonata. We feel compelled, therefore, to retain this 
species for the present, although the remark of Hansgirg, that it 
apparently belongs in the cycle of forms of U. zonata, may be jus- 
tified by future investigation. 
U. tenuissima differs from typical forms of U. zonata, besides 
being of a smaller diameter, in its deeper green color, in its gener- 
ally shorter cells and in its thin cell-wall. Nevertheless, certain 
young forms of U. sonata show a most perplexing similarity to 
the form described above. 
. ULOTHRIX AEQUALIS Kitz. Phyc. Germ. 197. 1845; Spec. 
Ale 347. 1849; Tab. Phyc. 2: p/. 89. f. r. 1852; Rabenh. 
' Krypt. Flor. Sachs. 1: 264. 1863. Wolle, F. ۷۷۰ Alg. 134. 
pl. 116. f. 3-5. 1887 
Myxonema aequale Rabenh. Deutsch. Krypt. Flor. 2^: 99 
1847. 
Hormiscia aequalis Rabenh. Flor. Eur. Alg. 3: 363. 1868. 
é un. — green in color; cells 13-16 م‎ in diameter, 
1-2 times a 
In a i uds flowing brook, attached to stones, Woodlawn, 
New York, May (571B). 
This specimen, when collected, was strikingly different in ap- 
pearance from U. zonata, but deteriorated speedily. When the 
station was revisited a few days afterward to obtain material for 
drawing and further study, all traces of the plant had disappeared. 
A specimen distributed as Hormiscia aegualis Tild. Am. Alg. 
132, is Microspora sp. 
دن 
4. ULOTHRIX OSCILLARINA Kütz. Phyc. Germ. 197. 1845; Spec. 
Ale 346. 1849; Tab. Phyc. 2: pl. 88. f. r. 1852. Rabenh. 
Flor. Eur. Ale 3: 366. 1868. Wolle, F. W. Alg. 137. ۶۰ 
116. f. 34-36. 1887. (?) 
Conferva oscillatorioides Agardh, Disp. Alg. Suec. 29. 1812; 
Syst. Ale 89. 1824. (?) Not Kitz. Ale Dec. 54. .1853 
(= Gloeotila oscillarina Kütz. Phyc. Gen. 245. 1843 = Stigeoclo- 
nium setigerum Kitz. Phyc. Germ. 198. 1845). 
Ulothrix oscillatorioides Crouan, Flor. Finist. 122. 1867. (?) 
