217 
S. Ulna, Zarb. Inf., 211, n. 295, t. 17, f. 1l. Lake, June-Septem- 
ber, 1902 ; plankton of Thames at Kew, August, 1902. 
S. splendens, K?z. Bac., 66, t. 14, f. 16. On Spirogyra, &c., in 
pots tank, on Cladophora i in lake and temperate house pools, 
August, 1902. 
B. Acus, Kitz. Bac., 68, t. 15, f. 1. Amongst Mesocarpus in lake, 
May, 1902 ; plankton of Thames at Kew, August, 1902 
Var. delicatissima, Sm. Plankton of Thames at Kew, 
August, 1902. 
Asterionella, Hassall, 1855. 
A gracillima, Heib. Consp., 68, t. 6, f. 19. Plankton of Thames 
at Kew (isolated), “ipa 1902. Abundant in plankton of Thames 
in December, 1 
Nitzschia, Hassall, 1845. 
N. Amphioxys ( Zhrb.), Sm. Diat., i., 41, t. 13, f. 105. Amongst 
Cladophora on imum of lake, January, 1902. 
N. sigmoidea (Nitzsch), Sm. Diat., i. 38, t. 13, f. 104. Lake and 
water-lily pond, September, 1902 ; plankton of Thames at Kew, 
August, 1902. 
N. linearis (Ag.), Sm. Diat., i., 39, t. 13, f. 110. Lake and water- 
lily pond, September, 1902. 
Nitzschiella, Rabenh., 1864. 
N. acicularis (Kiz.), Rabenh. Alg., i. 164. Lake and water-lily 
pond, September, 1902. 
Navieula, Bory, 1822. 
N. cuspidata, Ktz. Bac., 94, t. 3, f. 24, et 91. Amongst Oscillaria 
nigra in water-lily pond, September, 1902. 
N. elliptica, Ktz. Bac., 98, t. 30, f. 55. 
Forma minor, Rabenh. Middle tank of water-lily house, 
September, 1902. 
N. Bacillum, Eb. Mon 130, £&. 4, v., f. 8. Amongst Syne- 
chococcus and. Gloeocapsa, on walls of. tropical fern house, 
August, 1902. 
N. oe Kiz. Bac., 96, t. 21, f. 14. 
rectangularis, Rabenh. Amongst Oscillaria nigra in 
veri and water-lily pond, September, 1902. 
N. minutissima, Grun. in Wien. Verh., 1860, 552, t. 2, f. 3. 
— a mass of Huglenae on moist gravel of laboratory tank, 
ust, 1902 ; on the glass windows of many of the hotter houses 
(a. 7s , water-lily house),—almost colourless, present all the year 
nd; middle tank of water-lily house, September, 1902, 
