98 ZYGOPHYCER. 
“Tt forms large masses on the water, full of air-bubbles, being pale 
and yellowish above, and of a blackish green beneath. Filaments not 
lubricous, nearly equalling those of Spirogyra nitida, but with much 
longer articulations. When young the colour is of @ dull pale green, 
and about three imperfectly spiral lines of shining granules are with 
difficulty distinguishable, Afterwards these lines become more con- 
spicuous, the rest of the filament being now perfectly colourless, and 
their component granules larger, but their arrangement is still irregular. 
The filaments subsequently unite here and there, not by every articula- 
tion, and their connecting processes are usually nearer to one end of the 
vessicle than to the other. Such filaments are divaricated at the points 
of connection. In some of the combined articulations the contents 
appear unchanged, in others they form a mass of larger granules than 
in the lines, and some have a large oval sporidium which often swells 
the joint. Some traces of unchanged lines occur, now and then, in the 
fructifying vessicles.”—English Botany, 2nd ed., p. 176. 
Plate XL, fig. 1. a, sterile cells X 200; 8, ¢, d, e, conjugating cells 
X 200 ; f, zygospore x 400, After De Bary. 
Genus 47. ZYGOGONIUM. Kutz. (1843.) 
Cells cylindrical or barrel-shaped, with a compact, often many- 
layered glittering cell-wall. On each side near the middle an 
irregular chlorophyll. body, each furnished with a starch granule, 
both often confluent in an axile string (in the very thick-walled 
cells usually concealed by granules). Connection of the copu- 
lating threads ladder-like. The protuberances of the two con- 
tiguous inter-growing threads that receive the chlorophyll- 
contents are bounded by partitions into fructifying-cells, which 
then coalesce into a not-contracted zygospore. 
Zygogonium ericetorum. De Bary Conj. p. 79. 
Sterile cells, 14 to 2 times as long as broad. 
Zygospores subglobose or oblong, sporoderm rather thick, 
even. 
Sizz.—Cells -013 to -018 mm. diam. Zygospore -013 x -025 
mm. 
var. u. terrestris, 
Zygogonium ericetorum, Kutz. Tab. v. t. 10, Dickie Bot. Guide, 
296. Jenner Fl. Tunb. Wells, 184. Hass. Alg. 174, t. 41, 
£152; 
Zygogonium torulosum, Kutz. Tab. v. t. 14. 
Conferva ericetorum, Eng. Fl. v. 850; Harv. Man. 125; 
Dillw. Conf. t.1, Eng. Bot. Ist Ed., t. 1553, 2nd ed. t. 2473. 
Grey, Fl. Ed. 318. Grev. Crypt. Fl. t. 261 (?) Mack. Hib. 
224. Fi. Devon. ii. 51. Hook. Fl. Scot. ii. 81. 
Conferva alpina, Eng. Fl. v. 350. Harv. Man. 125. Grey. 
Se. Crypt. Fl. t, 261, f. 2. 
On heaths. 
