Freshwater Algse of 8. of England. By W. & G. S. West. 477 
genea, et atroccerulea, in una cellnlarum conjugatarum inclusis ; 
cellulis fructiferis valde inflatis circa zygosporas. 
Crass, fil. veget. 14-5-17 [x (plerumque 15-16 f) ; 
diam. zygosp. 23-26 fx (usque ad 29 [x long.). 
This species comes nearest to Z. melanospermum Lagerh. and 
Z. cyanospermum Cleve. It differs from the former in its narrower 
filaments, in its subglobose zygospores, and in having the fructiferous 
cells much inflated round the zygospores ; from the latter, in its 
narrower filaments and much smaller zygospores, which are not situ- 
ated in the conjugating tube between the filaments. 
4. Z. ericetorum (Kfitz.) Hansg. I. Ep. III. Pu., Th., Wi. 
5. Z . pedinatum (Vauch.) Ag. YI. IN. 
Genus Spirogyra Link. 
1. 8. tenuissima (Hass.) Kiitz. II. Ha., U., Wh. III. M. 
2. S. inflata (Vauch.) Kabenh. III. Ew., M. 
*3. 8. Spreeiana Kabenh. III. Ew. 
4. 8. Weberi Kfitz. II. Ku. III. Ka. 
*5. 8. calospora Cleve. 
The cells are 4 to 7 times longer than broad ; sporiferous cells 
very slightly inflated to accommodate the zygospore, which is a 
little broader than the vegetative cells. The zygospores were usually 
oblong-elliptic, and only 1 h times longer than broad although occa- 
sionally twice as long. The median spore-membrane is covered so 
densely with large somewhat angular scrobiculations of variable size, 
that its surface view appears a mere reticulation. Petit’s figure 
(Spirogyrae des envir. Paris, pi. ii. f. 13) of an enlarged portion of the 
zygospore of this species is very incorrect. 
Crass, cell, veget. 31-36-5 crass, cell, fruct. 41-52 p\ 
long, zygosp. 75-87 y , ; lat. zygosp. 40-50 [x. II. Ku. 
6. S. gracilis (Hass.) Kfitz. var. flavescens (Hass.) Kabenh. 
II. Ku. 
7. S. catseniformis (Hass.) Kfitz. III. M. YI. K 
8. S. a finis (Hass.) Petit. III. E., M. 
9. 8. varians (Hass.) Kfitz. II. Ku. III. B. VII. Street. 
10. 8. porticalis (Mfill.) Cleve. IY. He. 
11. 8. decimina (Mfill.) Kfitz. III. Eh. 
Var. cylindrosperma var. n. 
Yar. zygosporis exacte cylindricis, diametro 2-3^- 
plo longioribus, apicibus late rotundatis, cellulas 
fructiferas paene complentibus. 
Crass, cell, veget. 40-44 ix ; long, zygosp. 92-140 ix ; 
lat. zygosp. 39-43 p . II L El. 
12. 8. nitida (Dillw.) Link. II. Ha. III. FI., Wi. 
