BT G. I. PLAYFAIR. 129 



The ratio of length to breadth varies from 1'6 to 19 ill), as far 

 as can be determined from the figures given, lying evenly, there- 

 fore, within the generally observed limits for the species. I have 

 not come across this form. 



Var. NOTABILE W. West. (Text-fig. 17^). 



"Cellulis lateribus subrectis et incrassatis; membrana irregu- 

 lariter punctata. Long. 29/x, lat. 16-5/x." W. West. 



Journ. R. Micr. 8oc., 1894, p. 15, PI. ii., f.29. I have not met 

 with this form. 



OocYSTis SUBMARINA Lagerh. (PL vii., f.30). 



Lagerheim, Bot. Notiser, 1886, p.45, f.l; W^ittr. it Nordst., 

 Alg. aq. dulc. exsicc. No. 7 26; Wille, Zur Entwickl. d. Gatt. 

 Oocystis, Deutsch. Bot. Gesells., 1908, T. xv., the last being a 

 thorough investigation of this species, with a large number of 

 excellent figures. Lemmermann, Nord. Plankt., xxi,, p.l5, f.54, 

 55 (after Lagerheim). 



Cell. veg. 24 x 8, 25 x 12, 28 x 10//. 



Sydney Water-Supply (100). 



The cells vary from elliptic to linear-elliptic, with acutely 

 rounded ends. The chloroplast is a laminar, parietal band, very 

 narrow for the length of the cell (often one in each half of the 

 cell). Wille, I.e., pp.813, 820, gives two, long lists of sizes (in 

 eMenso) which may be summarised as long. 7-20, lat. 3^-9//, the 

 ratio of length to breadth being Iw to 

 2-1 :rO (averages of 9 and 10 records re- 

 spectively). It will be seen that, in this 

 respect, O. submaj-ma begins where O. 

 Xovce SeniHfn leaves off. G. S. West 

 reports it from the Yan Yean Reservoir, Text-tig. is. 



Melbourne (Journ. Linn. Soc, Bot., Vol. ^^- ^^'^'"narinaJ^gevh., 



^_, , , -v.T ".tr 1 . »- 1 o after Lagerheim. 



xxxix., p.75) at long.23-25, lat. 7|-8/x. ^ 



The axial ratio is nu)re than 3:1 in the Victorian specimens, and 

 in some of ours, indeed, the linear-elliptic form should be con- 

 sidered typical, the shorter and broader cells being practically 

 identical with O. Nov<i'. Semlue. In spite of its name, it is a 



