7 
Navicula forcipata Grev. 30 (11) s20. Too small (and marine) to be the sp. but 
has a resemblance. Only one specimen. 
ii Grevillei Ag. 55 (6:15:5) s10 and 20. 
e aridis KE. 75 (238). 
of “~- var. producta? 50 (8:12:3) s16. 
. major K. 190 (25:28:25) s7. 
. mesolepta E. 60 (8:12:9:12:9:12:8). 
ss oblonga K. 72 (9:11:9) s10. A small variety. 
s ovalis Hilse, 56 (34) s8 and 12. 
a Ouillensis (nov. sp.) 110 (10:30:10) s13. 
of scutellum O.M. (?) 33 (16) s14. 
A tenella Bréb. 29 (2:6:2) s10. 
Nitzschia hungarica Grun. 60 (..11:12:11..) s16 and 8. 
is thermalis (K) Grun. 48 (3:5:3) s16 and 0 (?). 
tryblionella Hantzsch. V. calida Grun. 
Pleurosigma attenuatum W. Sm. 
accuminatum (KK) Grun. 120 (4:14:4) s20. Sigmoid. 
. elongatum W. Sm. 260 (5:25:5) s17. 
Rhoicosphenia curvata Grun. 30 (5:10) s14. 
Stauronets crucigera Sm. 45 (5:14:5) s20 and stauros? 
s salina W. Sm. 45 (18) s20 and St. 
Tabellaria fenestrata K. 68 (6:33 :8:33 :6) $17. 
oe ovalis Bréb. 95 (66) s38 and 18; 62 (33) s3 and 18. 
‘‘ var. ovata K. 80 (60) s4 and 18; 50 (40) s3 and 18. 
ss = “ Brightwellat Sm. 58 (51) s3 and 18; 40 (28) s383 and 18. 
‘ x Crumena Breb. Nearly circular (?). 
s ‘“  minuta Breb. Like Brightwellii, but smaller (2?) 25 (19). 
S. Baileyana MacKay 155 (107) sl and 5 and 18; 100 (80) s75 (53) s2 & 18. 
Very abundant and contorted or twisted. 
S. biseriata Bréb. 160 (30:45:20) s2. 
S. limaris Sm. var. constricta 55 (14:13:14) s3. 
ee acus (K) Grun. 82 (3:5:3) s16; 100 (2:6:2) s16. 
danica (K) 110 (14:1:4:14) s12. 
5 pulchella (IK) 72 (6) s16. 
* nitzschioides Grun. 70 (3). (See Thalassiothrix.) 
: ning T2283 (36:3). 72 (82133) sli. 
Thalassiothrix nitzschioides Grun. 70 3); 45: (3) S13; 32 (4) sis. 
Vanheurckia vulgaris Thw. 50 (5:9:5) s?; 40 (5:9:5) s?; 30 (5:9:5) s?; 23 (4:8:4) s? 
ie 
DIATOMS FROM AIRDRIE, ALBERTA 
The diatoms in the list following were found in a collection made by Mr. H. 
C. Wheeler from a ditch near the C.P.R. track at Airdrie in November, 1920. 
Ampbphora ovalis K. 33 (9) s10. 
" var ayinis We 30 (6)rsi2- . 
161 
