30 Minnesota Algae 



B Plant mass colored 



a Plant mass blue-green, olive or yellowish-brown; cells 2-3.5 



mic. in diameter A. castagnei 



b Plant mass pale blue-green; cells 3-8 mic. in diameter 



A. pallida 

 c Plant mass pale yellowish-green or olive; cells 2-3 mic. in diam- 

 eter A. microspora 

 d Plant mass yellowish-brown or olive; cells 4-4.5 mic. in diam- 

 eter, irregularly scattered A. naegelii 

 II Plant mass more or less spherical 



1 Plant mass pale blue-green; cells 3-5 mic. in diameter 



A. stagnina 



2 Plant mass bright or dark emerald green; cells 5-6.5 mic. in diameter 



A. prasina 



70. Aphanothece saxicola Naegeli. Gatt. Einz.- Alg. 60. pi. i H. f. 2. 1849. 



De Toni. Syll, Algar. 5:81. 1907. 



Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 25. no. 1203. 1905; 

 Phyc. Bor.-Am. Fasc. 2t. no 1301. 1906. West and West. On spme Fresh- 

 water Algae from the West Indies. Journ. Linn. Soc. Bot. 30: 277. 1895. 



Plant mass mucous-gelatinous, colorless or yellowish, without definite 

 shape; cells 1-2 mic. in diameter, 2-6 mic. in length, somewhat cylindrical, 

 with rounded ends, single or in pairs, sometimes surrounded by many par- 

 tially dissolved sheaths; cell contents pale blue-green. 



Massachusetts. Forming soft masses of irregular form, floating among 

 other algae. Horn Pond. Woburn. September 1905. (Collins). California. 

 Walls of reservoir. Del Monte, Monterey County. September 1902. (Oster- 

 hout). West Indies. "In small masses of 70-120 mic. in diameter, amongst 

 mosses on trees. Rather scarce." Summit of Trois Pitons (4500 feet), 

 Dominica. November and December 1892. (Elliott). 



71. Aphanothece conferta Richter in Hauck and Richter. Phykotheka 



Universalis, no. 487. 1892. De Toni. Syll. Algar. 5: 84. 1907. 



Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 24. no. 1152. 1904. 



Plant mass gelatinous-mucous, membranaceous, expanded, dirty green 

 or olive brown; individual sheaths colorless, diffluent; cells 2.5-3 niic. in 

 diameter, 4.5-5.5 mic. in length, spherical or oblong, single or in pairs, 

 crowded in families; cell contents finely granular, pale blue-green or olive. 



California. On trunk of Bay tree. Strawberry Creek, Berkeley. March 

 1003. (Gardner). 



72. Aphanothece utahensis Tilden. American Algae. Cent. III. no. 297. 



1898. 



Plant mass 1-6 cm. in diameter, forming thin, gelatinous, brown and 

 blue-green membranes; cells 5 mic. in diameter, oval or nearly spherical, 

 single or in twos. 



