SPH.EROZOSMA. 213 



oblong, upper angles more broadly rounded than the 

 lower ones ; vertical view narrowly elliptic. 



Length 7'8-8'8pi ; breadth 9-10 ^ ; breadth of isth- 

 mus 2*5-3 VL ; thickness 3 '7 pi. 



ENGLAND. Stickle Tarn and Brother's Water, West- 

 moreland ! 



This tiny variety has a very different appearance from the 

 typical form, and bears a strong resemblance to Sph. vertebmtum 

 Ralfs forma minor West, from which it differs in its extremely 

 deep constriction. 



4. Sphaerozosma granulatum Roy & Biss. 



(PL CLX, figs. 6, 7.) 



Splicerozosma excavafum forma Javanica Xordst. Alg. et (liar. I, 1880, p. 3. 

 ''. XpJi. spinulosum Delp. in Wolle, Desm. U. S. 1884, p. 31, t. 4, f. 14. 

 Xph. granulatum Roy & Biss. Jap. Desm. 1886, p. 242, f. 17; Nordst. 



Freshw. Alg. N. Zeal. 1888, p. 28 ; De Toni, Syll. Alg. 1889, p. 791 ; 



Rov. Freshw. Alg. Enbridge Lake and Vicin. 1890, p. 335 ; Anderss. 



Sverig. Chlorophy. 1890, p. 9 ; West, Alg. Maine, 1891, p. 353 ; Alg. 



Engl. Lake Distr. 1892, p. 6 ; Alg. W. Ireland, 1892, p. 115 ; Liitkem. 



Desm. Attersees, 1893, p. 539 ; Roy & Biss. Scott. Desm. 1893, p. 10 ; 



West & G. S. West, Alga-fl. Yorks. 1902, p. 110; A1-. X. Ireland, 1902, 



p. 59 ; Alg. Ceylon, 1902, p. 193 ; Alg. Orkneys & Shct lands, 1905, p. 28. 



Cells small, about as long as broad, constriction deep 

 and open ; semicells elliptical, lateral margins rounded, 

 apex straight ; apical processes widely separated ; 

 semicells with a group of minute granules at each lateral 



O .( O 



margin, about 3 of which are visible ; semicells from 

 the side rounded, with about 6 small granules surround- 

 ing a central one. Chloroplasts axile. one in each 

 semicell, with a central pyrenoid. 



Zygospore cubical, smooth, with one or two short, 

 stout, and blunt spines on each angle (Roy}. 



Length 8-9 \i ; breadth 8-1 0(i ; breadth of isthmus 

 4-5 ;JL ; length and breadth of zygosp. 14 '5 \L ; length of 

 spines 3 '5 \i. 



ENGLAND.- -Wastdale, and in the plankton of Enner- 

 dale Water, Cumberland ! Bowness, and in the plankton 

 of Hawes Water and Codale and Easedale Tarns, West- 

 moreland ! Hampsfell, Lancashire ! Pilmoor, N. Yorks ! 



