Algse of the English Lake District. Bg Wm. West. 717 
M. parvula Hass. 
forma sporis rotundo-ellipticis. 
Long. spor. 15-16 p; lat. spor. 12 * 5—14 p; Bassen- 
tli waite Water. 
M. quadrangulata Hass. [M. quadrata (Hass.) Wittr.] 
forma minor. 
Crass, cell, veget. 7-7 • 5 p ; diam. spor. 28-30 p. Bassen- 
tli waite Water. 
M. viride (Kiitz.) Wittr. Bn. 
M. gracillima (Hass.) Wittr. B., H. (at 2400 ft.). 
? M. elegantula Wittr. 
Crass, cell, veget. 5 p (sterile). Bn. 
All tHe species of Mougeotia were in abundant conjugation except 
the last. 
Order Zygnemacejs. 
Genus Sirogonium Kiitz. 
S. stieticum (Eng. Bot.) Kiitz. H. 
Genus Spirogyra Link. 
S. tenuissima (Hass.) Kiitz. 
Forma cellulis fructiferis subtumidis. 
Lat. cell, fruct. 27-30 p ; long, zygosp. 60-64 p ; lat. 
zygosp. 23-25 p. Bn. 
This approaches var. plena Lagerh. (Contrib. FI. Alg. del 
Ecuador, p. 7). 
8. jlavescens (Hass.) Kiitz. 
forma. Lat. cell. veg. 14-16 p ; long, zygosp. 53-55 p ; 
lat. zygosp. 22-23 p. Esthwaite Water. 
S. gracilis (Hass.) Kiitz. 
Forma zygosporis solum diametro lj-plo longioribus. 
Lat. cell. veg. 19 p ; lat. cell, fruct. 39-41 p ; long, 
zygosp. 42-44 p; lat. zygosp. 27-30 p. Bn. 
S. varians (Hass.) Kiitz. Black Sail Pass. 
Forma cellulis sterilibus minoribus et zygosporis diametro 
lj-plo longioribus. 
Lat. cell. ster. 21 p ; long, zygosp. 34 p ; lat. zygosp. 
25 p. Bo. 
*8. Lutetiana P. Petit var. minor var. n. 
Var. duplo minor quam forma typica, cellulis vegetativis 
diametro 8-plo longioribus ; zygosporis cylindrico-oblongis, 
diametro 3-4-plo longioribus. 
Lat. cell, veget. 19 p ; long, zygosp. 50-63 p\ lat. 
zygosp. 18-19 p. Bo. 
S. nitida (Dillw.) Link. Bn. 
Only occasional zygospores. 
