290 



JJ\^s/ : Phvtophiuktou of Kiii^/is/i Ijikc nis/n'c/. 



Soc. Bot.'. XXIX.. \\ 172. t. 22, t. ij ; ihid. WW.. 



1003. p. 543, t. 17. f. 1-4. 



This species is fairly general in the plankton of the linghsli 

 lakes, and a particularly fine form is abundant in Wastvvater 

 (Fig. 5 e). This form attained a diameter of 80 //. with th(> 

 spines. 



15. Staurastrum brevispinum Breb. forma major. Cells 

 very large, but otherwise typical. Long. 59-63 /x ; lat. 52-57 fi. 

 This form was abundant in the plankton of Brothers' 

 Water (Fig. 6 e). In size it approaches var. altum W. & G. S. 

 West, but has not the proportions characteristic of that \'ariety. 



16. Staurastrum Ophiura Lund, in Xov. Act. R. Soc. 

 Scient. L'psala, ser. 3, VUL, 1871, No. 2. p. 69, t. 4, f. 7. 



This species was only observed in the plankton of Easedale 

 Tarn. It has been seen in no other part of the Lake District, 

 and this is its first record for England. This is the more 

 remarkable since St. Ophiura is one of the most conspicuous 

 constituents of the Scottish and Welsh plankton. The speci- 

 mens observed were 9-rayed, and had a diameter (with processes) 

 of 142 fJ^. 



17. Sph.erozosma vertebratum Ralfs var. punctulatum 

 W. & G. S. West in 'Trans. Bot. Soc. Edin.', XXIII., 1905, 

 p. 28. S. punctulatum West in * Journ. Bot. Dec. 1891, t. 315, 

 f, I, 2. 



This variety occurred in both Brothers' Water and Enner- 

 dale Water, but was much more abundant in the latter. The 

 cells are more angular than those of the type-form, and the 

 punctulation of the cell-wall is a marked feature of the variety. 



18. Eudorixa elegaxs Ehrenb. 



We find this member of the Volvocaceae fairly general in 

 the plankton of British pools and lakes. It always attains its 

 greatest maximum in the autumn, during the decline of tem- 

 perature. 



Huitfeldt-Kaas (1. c. 1906, p. 36) has placed SphcBVocystis 

 Schroeteri in the Volvocaceae under the name of ' Gloeococcus 

 mucosus A. Br.', but we are inclined to think that he has con- 

 fused this characteristic plankton-alga wdth Eudorina elegans. 

 Wesenberg-Lund also believes this confusion to have taken place. 

 We should not be surprised if Huitfeldt-Kaas had done this, 



Naturalist 



