404 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



{Vol. 10 



The alga was present in abundance, but there were no spores 

 so that its real identity is uncertain. The trichomes were quite 

 straight, with a conical apical cell. 



A. circinalis Rab. 



Strawberry Lake. 



A. flos-aquae (Lyng.) Breb. var. gracilis Kleb. in Flora 80: 

 268. pi 4, f. 23, 24. 1895. 



Frettem Lake; Carpenter Lake; Wheeler's Pond, I; Coe Lake. 



This species was present in many of the collections although 

 it was fruiting only in the one from Frettem Lake. The tangled 

 trichomes were 4-6 \l in diameter, and closely resembled Kle- 

 bahn's figure. The cells were more frequently spherical than 

 elongated, but in all other characters the specimens agreed very 

 well. One sample from Carpenter Lake contained a form of 

 Anabaena with trichomes twisted into irregular spirals. Its 

 trichomes were 5-6 y. in diameter, and somewhat immature 

 spores were present, which were kidney-shaped but a little stouter 

 than those of A . flos-aquae var. gracilis from Frett em Lake. The 

 specimens were rather unsatisfactory, but the form is provision- 

 ally placed here. 



Var. Treleasii Born, et Flah. 



Diam. trich. 3.5-4 n; spores 7 X 19 pi. 



Strawberry Lake; Wheeler's Pond, I. 



The coiled filaments of the specimens seemed to agree very 

 well with this variety, except that the cells, although sometimes 

 longer than broad, were usually approximately spherical. Spores 

 were not observed in the material from Wheeler's Pond. 



A. Lemmermanni Richter. 



Jarves Lake; Lake Y or South Twin Lake, near Robinson; 

 Carpenter Lake. 



A. macrospora Klebahn var. crassa Klebahn in Flora 80: 

 270. pi 4, /• 19, 20. 1895. PI. 21, figs. 17, 18. 



Diam. trich. 10 n; long. cell. 9-10 ix; heter. 12 n; spor. (immat.) 

 25 X 15 ix. 



Crooked Lake. 



The trichomes were slightly larger than Klebahn's examples, 

 but otherwise were very similar. The alga is striking by reason 

 of its long rigid filaments, uniform except for the very rare 



