148 Ulothricaceae 



Conferva sonata Web. & Mohr, Naturhist. Reise Schwed. 97. 

 pi. 1. f 7. 1804. Lyngb. Tent. Hyd. Dan. 136. //. 4.3. 18 19. 

 Agardh, Syst. Alg. 90. 1824. 



Conferva luccns Dillwyn, Brit. Conferv. pi. 37. 1805. Eng. 

 Bot. pi. 1633. 1 806. 



Myxonema zonatum Fries, Syst. Orb. Veg. 1 : 343. 1825 ; 

 Flor. Scan. 329. 1835. Rabenh. Deutsch. Krypt. Flor. 2 2 : 99. 



1847. 



Lyngbya sonata Hass. Brit. F. W. Alg. 220. pi. 39. 1845. 



Hormiscia sonata Aresch. Act. Reg. Soc. Sci. Upsal. III. 6 1 : 

 No. 2. p. 12. pi. 2. 1866. Rabenh. Flor. Eur. Alg. 3 : 362. 

 1868. Cooke, Brit. F. W. Alg. 179. pi 69. 1883. DeWild, 

 Flor. Alg. Belg. 36./. 12. 1896; Flor. Buitenz. 3: 57. f. 7. 1900. 



The filaments form yellowish-green, fluctuating masses, 

 .5-2 dm. in length; cells cylindrical or somewhat swollen, 1 1— 

 45/i in diameter, ^3-1^ (in young filaments 3) times as long; 

 the cell-wall at first thin, with age growing thicker, especially in 

 the circumferential region of the septations, so that the larger cells 

 appear to be constricted at the joints ; chromatophore forming a 

 broad or narrower girdle, enclosing several large pyrenoids (pi. 



20. f I-f). 



Exsicc: Phyc. Bor. Am. 19. A. Fairfield, Conn., Jan. 1894. 

 (I. Holden); Not ig. B. (=Microspora amoena). Tild. Am. Alg. 

 7. Minneapolis, Minn., April, 1894; 131. (var. valida Nag.) Lake 

 Superior, Minn., Jul. 1896. (A. H. Elftman). 



On stones or wood, in quiet or rapid waters. 



Vermont : St. Johnsbury, April (672) ; North Hero, June 

 (681) ; Alburg, Lake Champlain ; 30 June (683). 



Connecticut : Derby, April (538) ; Thomaston, May (567). 



New York : Williamsbridge, April (95, 294) ; Woodlawn, 

 May (596), Bronx Park, May (373) ; Central Park, March (260), 

 April (323, 525, 84), May (104, 381, 382, 386, 594), June (614, 

 619). 



New Jersey: Nordhoff, May (356). 



Idaho: Nez Perces county, 1896 (A. A. Heller). 



Small forms of this species make their appearance in the drink- 

 ing fountains and horse troughs of New York in early spring. At 

 first one would be inclined to refer these forms to some smaller 

 species, but prolonged observation of the development is suffi- 



