i82 Minnesota Algae 



Bull. Torr. Bot. Club. 7: 44. 1880. (Sphaerozyga saccata 

 Wolle). Wittrock and Nordstedt. Algae Aq. Dulc. Exsicc. no. 397. 

 1880. Wolle. Fresh- Water Algae N. S. 290. pi. 199. f. I. 1887. Wolle 

 and Martindale. Algae. Britton's Catalogue of Plants found in New 

 Jersey. Geol. Surv. N. J. 2: 607. 1889. De Toni. Syll. Algar. 5: 

 432. 1907. 

 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. i. no. 30. 1895. 



Plate VIII. fig, 21, 22. 



Colonies 2-6 mm. in diameter, up to i dm. in length, consisting of 

 elongated, vertical, somewhat membranaceous, soft tubes, closed at the 

 apex, cylindrical or variously constricted, more or less aggregated; trich- 

 omes 4-5 mic. in diameter, numerous, erect, parallel or slightly curved; 

 cells oblong or cylindrical, closely connected; heterocysts 6 mic. in diame- 

 ter, oval or somewhat spherical, yellow or pale orange; gonidia 7 mic. in 

 diameter, 15-22 mic. in length, numerous, cylindrical, catenate. 



New Jersey. At first attached, afterwards floating free. Along the 

 shores and in the shallow water of Cranberry Pond. (Wolle). 



Genus NODULARIA Mertens. 

 Jiirgens, Alg. Aquat. Dec. XV. no. 4. 1822. 



Filaments free; sheaths colorless, close, usually thin, mucous, some- 

 times diffluent; trichomes more or less straight; cells short, depressed, 

 disc-shaped; heterocysts depressed; gonidia spherical, somewhat spherical 

 or disc-shaped, developed in series between the heterocysts; wall of go- 

 nidium smooth. 



I Trichomes less than 8 mic. in diameter. 



1 Filaments 4-6 mic. in diameter; gonidia 6-8 mic. in diameter, some- 



what spherical N. harveyana 



2 Filaments 6-7 mic. in diameter; gonidia 7-10 mic. in diameter, spheri- 



cal depressed N. sphaerocarpa 



3 Trichomes 6-8 mic. in diameter; cells short, about half as long as wide 



N. paludosa 



II Filaments more than 8 mic. in diameter. 



1 Trichomes 7.5-9.5 rnic. in diameter; cells nearly as long as broad 



before division N. hawaiiensis 



2 Filaments lo-ii mic. in diameter; gonidia 10-12 mic. in diameter, 9 



mic. in length, spherical depressed, in series N. armorica 



3 Filaments 8-18 mic. in diameter; gonidia 12-15 niic- in diameter, 6-10 



mic. in length; somewhat spherical or elliptical 



N. spumigena 



4 Trichomes (?) 33-38 mic. in diameter; cells short 



N. mainensis 



340. Nodularia harveyana (Thwaites) Thuret. Essai Class. Nostochinees. 

 Ann. Sci. Nat. Bot. VI. i: 378. 1875. Bornet and Flahault. Revis. 



