176 ULOTHRICACEAE 
Exsic.: Phyc. Bor. Am. 679, Melrose, Mass., March, 1894 
(F. S. Collins). 
Forming floccose masses in brooks and in stagnant waters. 
MassacHusETTs: Ipswich, May (558B). 
New York: Botanical Garden, May (376A, 407), June (609). 
New Jersey: Grantwood, April (530A); Edgewater, March 
(66B). | 
It is to be suspected that Scandinavian authors would include 
under this name the form which we have determined as M. floccosa. 
for in the vegetative condition there is the most perplexing simi- 
larity between the two forms. Indeed we have found forms cor- 
responding to M. floccosa, M. Willcana, and M. stagnorum all 
mixed together, and forming what looked, at first sight, like a 
graded series of growth forms. 
Nevertheless, in the fruiting condition, M. /foccosa is easily dis- 
tinguished from 77. Willeana by its much larger akinetes, and it is 
probable that by more exact and extended field study they could 
be better distinguished when in the vegetative state. 
This problem did not present itself until too late for more 
thorough field observations to be made in preparation for this 
paper. 
7. MicRosPORA STAGNORUM (Kütz.) Lagerh. Ber. Deutsch. bot. 
Gesell. 5: 417. 1887 ; Flora, 72: 208. 1889. Hansgirg, Prod. 
Alg. Böhm. 2: 222. 1893. DeToni, Syll. Alg. 1: 229. 
1889. 
Conferva tenerrima stagnorum Kitz. Alg. Dec. 56. 1833; 
Flora, 16: 700. 1833 
Conferva stagnorum Kitz. Phyc. Gener. 257. 1843. Wille, 
Ofvers. Vet.-Akad. Förhand. 1881°: 20. pl. .و‎ f. 12-27. pl. ro. f. 
50. 1881. Hansg. Prod. Ale Böhm. 1: 75. 1886. 
Gloeotila stagnorum Kitz, Phyc. German. 191. 1845. 
Ulothrix tenerrima stagnorum Kitz. Spec. Alg. 346. 1849. 
Ulothrix stagnorum Kitz. Tab. Phyc. 2: 27. pl. 87. کر‎ 2. 
1852. Rabenh. Krypt. Flor. Sachs. 1: 264. 1863; Flor. Eur. 
Alg. 3: 366. 1868. 
Ulothrix tenerrima Rosenv. Bot. Tidssk. I1: 121. pl I. f. 
IT-14, 17-21. 31879. 
