4 
Transactions of the Society, 
Tolypothrix lanata Wartm., H. 
Trichome very slender, single, or sometimes two more or less 
parallel included in a sheath; not more than 10 in diameter; 
pseudocysts about as long as broad ; heterocysts few and distant. 
Sheath varying greatly in width, pale yellow, ultimately brown. 
'J'richome olten projecting a long way beyond the sheath. Floating 
on moor-pools, or attached to aquatic vegetation. Under this species 
Bornet and Flahault include T. flaccida Ktz., T. muscicola Ktz., 
T. coactilis Ktz., T. pulchra Ktz., T. segagropila Ebb., and others. 
Nostocace^. 
Aphazinomenon flos-aqum Kalfs, H. 
Cylindrospermum macrospermum Ktz., H. 
Nodularia sp., H. 
A species of this chiefly brackish- water genus was seen occasion- 
ally in bog-pools in the New Forest; but, as neither spores nor 
heterocysts were observed, specific determination was impossible. 
Fediastre^. 
Pediastrum Boryanum Turp., H. 
„ rotula A. Br., H. 
Staurogeneis rectangularis A. Br., H. Fig. 5. 
This rare organism was only very seldom seen in a gathering 
from a pool near Beaulieu. Of its systematic position I am very 
doubtful. It seems to me not improbable that it may be an early 
stage of a Pediastrum, and it is placed near this genus by Braun, but 
his description (Alg. Unicell., p. 70) is very imperfect. It bears some 
resemblance to Merismopedia, but the colour of the endochrome is 
chlorophyll-green, not blue-green. It agrees fairly well with Cooke’s 
description (‘Freshwater Algae,’ i. p. 46, pi. xviii. f. 3); but the 
coenobe is certainly not “ cubical.” The colony is tabular, like that 
of Pediastrwn,, Sihont 110 x 75 //,, elliptical with truncated ends, and 
contains, in the specimens observed, sixteen pseudocysts, arranged in 
four subfamilies of four each, the whole inclosed in hyaline jelly. 
The pseudocysts are oblong and somewhat curved, or bean-shaped, 
about 20-22-5 x 10 yu,. It was first observed in these islands by 
Archer, but he gives no locality ; the only British habitat yet re- 
corded of which I am aware is by Marquand, near the Land’s End, 
Cornwall. 
Pandorine.®. 
Eudorina elegans Ehrb., H. 
Gonium pectorale Mull., H, 1). 
