128 



Chlorophycece 



are often very long and the zygospore is large and ellipsoidal, frequently with 

 one or two mamillate protuberances at the poles ; length of zygosp. 35 72 /*, 

 breadth 1640 ^ (fig. 46 A). D. Icevis (Kiitz.) W. & G. S. West is a larger 

 species with shorter cells, which are 20 26 ju in thickness and 2| 4 times 



Fig. 46. A, Debari/a gli/ptox-perma (De Bary) Wittr., from Fairfield, Westmoreland 

 (x275). B, D. calospora (Palla) W. & G. S. West, from Pilmoor, N. York*. 

 ( x430). C E, D. hci-is (Kiitz.) W. & G. S. West, from Mitchain Common, 

 Surrey; C, x 180; D, x250; E, mature zygospore, x 430. F I, D. Desmidi- 

 oides W. & G. S. West, from near the Lizard, Cornwall ( x 430). 



longer than the diameter. The zypospore is ellipsoidal (44 50 p x 29 36 p.) 

 with a scrobiculate middle coat (fig. 46 C E). D. calospora (Palla) W. & 

 G. S. West is 11 13 p. in diameter; the zygospores are subglobose or ellip- 

 soidal, 18 26 /x in diameter, and ornamented with large scrobiculations 



