PrATE Sl: 
Fig. 1.—Cyclotella Quillensis, L. W. Bailey, n. sp. 
Fig. 2.—Chaetoceras n. sp.? 
Fig. 3.—Surirella Baileyana, flat form. 
Fig. 4.—Surirella Batleyana. 
Fig. 5.—Surirella Baileyana, doubled. 
Fig. 6.—Surirella Baileyana, partly twisted. 
Prats TI: 
Fig. 1.—Navicula cuspidata K. var. ambigua E. 600. Measurements 88 (5:4:24:4:5). 
Fig. 2.—Navicula cuspidata K. var. Kendalli McK. (Showing the striated valve and 
craticular plate.) 457. Measurements 153 (18:33:13). 
Fig.3.—Navicula cuspidata K. var. Kendalli McK. (craticulated). 455. Measurements 
195 (13:39:13). 
Fog. 4.—Navicula cuspidata K. var. Kendalli McK., f. parallela. 452. Measurements 
184 (12:38:12) s10 to 12 or 18. 
Fig. 5.—Navicula cuspidata K. var. Kendalli McK., f. radiata. 456. Measurements 
ig leg S el )rsiatol 2: 
All the above examples of N. cuspidata were collected at Airdrie, Alberta, by H. C. Wheeler 
and photographed by O. Kendall. 
