42 BRITISH DESMIDIACE^l. 



6. Spirotaenia eboracensis G. S. West. 

 (PI. Ill, figs. 4-6.) 



Spirotxnia minuta Thur. var. eboracensis West & G. S. West, Notes Alg. 



I, 1898, p. 2 tsep.) ; West & G. S. West, Alga-fl. Yorks. 1900, p. 40. 

 Spirotxnia eboracensis G. S. West in Liitkem. Gatt. Spirotuen. II, 1903, 



p. 9 (sep.), t. 11, f. 7. 



Cells small, about 4 times longer than their diameter, 

 fusiform-elliptic, with rounded apices ; chloroplast 

 parietal, rather narrow, with 4-4^ revolutions. 



Zygospore unknown. 



Length 30-32 /* ; breadth 7-8 p. 



ENGLAND. Cam Fell, W. Yorkshire ! 



Not uncommon among Cylindrocystis craasa, Netrinni 

 Digitus, Hyalothecu dissiliens, etc., in peat hogs. 



We agree with the recent suggestion of Liitkemiiller that 

 ill is plant should be regarded as a species distinct from 

 Spirut&nicb minuta. It is distinguished by its relative short- 

 ness in proportion to its breadth, and by the outward form of 

 the cell. 



7. Spirotsenia turfosa West & G. S. West. 

 (PI. II, fig. 11.) 



Spirotsenia turfosa West & G. S. West, Notes Alg. I, 1898, p. 2 (sep.) ; 

 Alga-fl. Yorks. 1900, p. 40. 



Cells of medium size, about 12 times longer than 

 their diameter, subcylindrical, elongate, almost straight 

 or slightly curved, at each pole gradually attenuated, 

 apices rounded ; chloroplast parietal, rather broad, 

 making only l-J-2 revolutions, pyrenoids small and 

 scattered. 



Zygospore unknown. 



Length 100-102 ^ ; breadth 7'5-8*5ju; breadth of 

 apices about 4/n. 



ENGLAND. Ilkley, W. Yorkshire ! 



& 



This species, which was found in peaty pools, appears to 

 come nearest to S. parvnla Arch., but is of much larger 

 si/A-, is proportionately longer, and has more rounded and 

 relatively wider ends. It differs from S. fusiform!* in its 

 larger size, its more rounded poles, and in having more turns 

 of the chloroplast. 



