476 
Transactions of the Society, 
*5. IT. calcarea Wittr. VI. N. 
6. If. capucina. III. Ew. VI. N. 
7. If. quadrangulata Hass. III. Dj. 
8. If. viridis (kiitz.) Wittr. I. Ep. III. Ew., Pu., Th., We. 
9. If. gracillima (Hass.) Wittr. I. Ep. III. C., Ew., Wi. 
Genus Gonatonema Wittr. 
1. G. Boodlei sp. n. 
G. cellulis vegetativis diametro 12-15-plo longioribus ; 
aplanosporis maturis e fronte et e latere visis ellipticis, apicibus 
late acuteve rotundatis, membrana distincte punctata, lutes- 
cente. 
Crass, fil, veget. 5-5 * 5 n ; long, aplanospor. 17-23 ji 
(plerumque 21 fi) \ lat. aplanospor. 13-17 p (ple- 
rumque 15 f). III. M. 
This interesting genus has been but once previously found in this 
country, when Hassall (1845) described from Notting Hill a jlant 
which he named Mesocarpus notabilis, and which has since been 
placed by Wittrock (1878) under Gonatonema as G. notabile (Hass.) 
Wittr. G. Boodlei differs from G. ventricosum Wittr. in being 
slightly smaller, and in having elliptical aplanospores when seen from 
either the front or side ; these aplanospores are never oblique, the 
apices are never truncate, and the spore-membrane is punctate. It 
was found in abundance mixed with Spirogyra sp. in a gathering 
made by Mr. L. A. Boodle in 1894 in a ditch on Mitcham Common, 
Surrey. 
Sub-fam. Zygneme2e. 
Genus Debarya Wittr. 
1. D. glyptosperma (De Bary) Wittr. VI. N. (very fine, April 
1897). 
2. D. Isevis (Kiitz.) nob. [Mougeotia Isevis (Kiitz.) Arch.]. 
III. M. 
Crass, fil. veget. 25 p ; spor. 42-50 x 28-32 /a. 
There seems to be no doubt whatever that this plant is a true De- 
barya , as the whole of the contents of the conjugating cells unites to 
form a true zygospore. The adult zygospores are dark coloured, 
with thick walls, and are ornamented with large scrobiculations. 
Genus Zygnema Ag. ; em. Be Bary. 
1. Z. anomalum (Hass.) Cooke. IV. Ks. 
2 Z. leiospermum Be Bary. III. Ew. VIII. T. 
3. Z. atroc'xmdeum sp. n. 
Z. cellulis vegetativis diametro 2J-5-plo longioribus; 
zygosporis globosis vel subglobosis, membrana lrevis, homo- 
