ZYGNEMACEA, 81 
var. c, stagnale. Kirsch. 
Sterile cells ‘01 mm,, 3 to 4 times as long. 
- Tyndaridea stagnalis, Hass. Alg. 162, t. 38, f. 9. 
Tyndaridea stagnicola, Hass. Ann. N. Hist. x. (1842) p. 42. 
Jenner Fl. Tunb. Wells, p. 182. 
It will be seen from the above that this is a variable species, of which 
two of the three varieties are British. These are by no means un- 
common, often mixed with other filamentous alge, and can scarcely be 
confounded with anything else, even when sterile. 
Plate XXX. fig. 3. a, portion of sterile thread x 400; 6, portion 
of fertile thread with zygospores X 400. Fig. 4, var. subtile. a, portion 
of sterile threads X 400; b, conjugating threads and zygospores X 400. 
Fig. 5, var. stagnale. a, portions of sterile threads X 400; 5, fertile 
cells with zygospores X 400. 
Zygnema anomalum. (Hass.) 
Sterile cells equal, or nearly twice as long as broad; cytio- 
derm thick, lamellose. 
Zygospore globose, olivaceous (sporoderm distinctly punc- 
tate ?). 
ne Cells 025 mm. diam., with mucous sheath about 
double ; zygospore ‘026 mm. diam. 
Tyndaridea lutescens, Hass. Alg. t. 38, f.4. Dickie Bot. 
Guide 296. 
Tyndaridea cruciata, Harv. Man. p. 141. 
Tyndaridea abbreviata, Hass. Ann. Nat. Hist. x. (1842) p. 43. 
Tyndaridea anomala, Hass. Alg. t. 38, f. 2-8. Jenner Fl. 
Tunb. Wells, 182. Ralfs, Eng. Bot. Supp. t. 2899. 
In boggy pools, 
The British species is the Tyndaridea anomala of Hassall and Ralfs, 
and not the Zygnema anomalum of Continental botanists, which species 
has the zygospore produced in the conjugating canal. The following is 
the original description published by Ralfs in the supplement to “ Eng- 
lish Botany ” :— 
“Tt forms large, dark green masses in shallow pools on heaths, The 
filaments are stout; under the microscope each is found to be enclosed 
in a hyaline sheath, which extends on each side about half the breadth 
of the coloured portion, and is always more or less waved or scolloped. 
At first it is nearly even, but it gradually becomes more and more irre- 
gular, and the conjugating specimens are almost denuded. The joints 
of the filament are usually about equal in length and breadth, but 
sometimes twice as long as broad. The endochrome is blackish green, 
and at first quadrate, when it completely fills the joint, but its division 
into two portions gradually becomes apparent until two stella, but less 
distinct than those in the other species, are at last developed, when con- 
jugation takes place in the usual manner. The spores, which are 
globular, are contained in the joints of one of the connected filaments. 
Not unfrequently the tubular processes are themselves converted into 
cells containing endochrome. 
“Tn its early state this plant is so different in appearance from the 
other species, that at first sight its proper situation is scarcely appa- 
