17. Gonidia in series A. Felisii 



17. Gonidia solitary 18 



18. Vegetative cells 4/x in diameter, 4— 6/oi long; gonidia slender, 6m in 

 diameter and up to 56— (70)/i, long A. Augstumalis var. marchica 



18. Vegetative cells 4-6/u. in diameter; gonidia larger, 



7-8-15m in diameter 19 



19. Vegetative cells 4-6^ in diameter; gonidia more than twice the 

 diameter of the vegetative cells A. Levanderi 



19. Vegetative cells 5-6;^ in diameter; gonidia less than twice the 

 diameter of the vegetative cells A. affinis 



20. Gonidia developing adjacent to the heterocysts 21 



20. Gonidia developing remotely from the heterocysts, scattered 25 



21. Vegetative cells globose or barrel-shaped 22 



21. Vegetative cells cylindrical A. subcylindrica 



22. Vegetative cells 4-6,ci in diameter 23 



22. Vegetative cells larger 24 



23. Gonidia cylindrical, with lateral margins parallel A. oscillarioides 



23. Gonidia elongate-ovate, with lateral margins convex A. torulom 



24. Vegetative cells 7.5-9/ti in diameter; gonidia 



11.5-13-( 17)/i in diameter A. lapponica 



24. Vegetative cells 12/x in diameter; gonidia 15-20^ in diameter. A. Bornetiana 



25. Vegetative cells cylindrical 26 



25. Vegetative cells ovate, barrel-shaped, or truncate-globose -27 



26. Gonidia usually in series, 10-12^ in diameter, with a smooth outer 

 membrane; vegetative cells 6-7/a in diameter A. Felisii 



26. Gonidia 1 or 2 together, 3.7^-(7)/i in diameter, with a rough 



outer membrane; vegetative cells 3— 4/u. in diameter A. verrucosa 



27. Trichomes lying somewhat parallel in a thin mucilaginous layer, 

 usually extending over the surface of large filamentous algae or 



stems of aquatic plants; heterocysts round, 4-6fj. in diameter _ A. inaequalis 



27. Trichomes not parallel; irregularly entangled 



or solitary among other algae 28 



28. Heterocysts spherical - A. affinis 



28. Heterocysts elongate-ovate or ellipsoid 29 



29. Gonidia in series, ovate or subglobose -30 



29. Gonidia 1 or 2 together, elongate to ^ubcylindric A. aequalis 



30. Gonidia barrel-shaped, 7.5-14ai long A. variabilis 



30. Gonidia oblong, often with retuse margins "A. catenula 



Anabaena aequalis Borge 1907, p. 65 

 PL 115, Figs. 1, 2 



Trichomes straight, forming a small plant mass, or scattered 

 among other algae; cells somewhat quadrate or barrel-shaped, 

 (4.5)-5.5-7.5/-t in diameter, 7.6-8.5;u, long; heterocysts ovate to sub- 

 cylindric, (5.5)-8/a in diameter, (10)-13-(15.2)yui long; gonidia 

 cylindrical, remote from the heterocysts, the wall smooth and color- 

 less, 5-7.6/x in diameter, ( 21) -35-41- ( 49.4 ))li long. 



Tychoplanktonic; intermingled with other algae in shallow water 

 in Sphagnum bogs. Wis. 



1512 1 



