ALGOLOGICAL NOTES 



331 



Mr. D. J. Scourfield has sent me a drawing of this species, which 

 he has observed in pools in Essex. 



8. Pteeomonas Chodati Lemm. /. c. 

 p. 94. P. angulosa Chodat, 1896. Long. 

 cell, sine integ. 13*5 fx, cum integ. 19 // ; 

 lat. cell. 9'2 /x, cum integ. 21 ^ ; crass, cell, 

 sine integ. 6 /x, cum integ. 12 /x. (Fig. 5, 

 C and D.) 



Hab. In the lakes at Great Barr Park, 

 Staffordshire. (Oct. 1911.) 



In this species, as in Pteromonas angu- 

 losa, the cells are compressed, but the 

 outstanding membrane is of an entirely 

 different character. Quite apart from 

 differences in outward form in the front 

 view (compare figs. 5, A, and 5, C), in the 

 side view there are tw'O large papilla-like 

 protuberances on each side (fig. 5, D). I 

 have only seen a few specimens of this 

 species, and so far have been unable to 

 satisfy myself w^hether the protuberances 

 so clearly visible in the side view repre- 

 sent ridges extending across the broad 

 sides of the organism, or whether they 

 actually represent two pairs of isolated 

 papillae on each broad side. 



The chloroplast is very similar in both ^^f '^^3°^* ^""^ ''^^ '''^'^^' 

 P. angulosa and P. Chodati, and in each 

 case contains a conspicuous pyrenoid. 



9. AsTEROCYSTis HALOPHiLA (Hansg.) Forti, Syll. Myxophy. 

 1907, p. 691. Allogonium halophihcm Hansg. Long. cell. 8-24 

 (plerumque 11-12) /x; lat. cell. 7-17 (plerumque 11-12) /x ; crass, 

 fil. 13-21 fx. 



Hab. Epiphytic on the older filaments of Cladopliora crisjmta 

 at Studley, Warwickshire. (Nov. 1910 ; W. B. Grove.) 



This Alga, which is a typical member of the Chroococcaceae, 

 has not previously been observed in the British Islands. In his 

 original description Hansgirg mentions the presence of "pyre- 

 noids " 3 /x in diameter, but this must be an error, the " pyrenoid" 

 probably referring to the " central body " of the cell. Hansgirg 

 has also described a var. stagnalis of this species (c/. Hansg. Prodr. 

 Algenfl. Bohm. ii. p. 132), in which the cells are spherical or 

 spherical-compressed and 5-6 /x in diameter. This variety was 

 described as occurring " in Cladophoris in stagno " in Bohemia. 



The habitat of the Warwickshire specimens was exactly that 

 of var. stagnalis, but notwithstanding the fact that they were 

 living in perfectly fresh water, they must be referred to the type 

 on account of the size and general proportions of the cells. 



Fig. 5.— A and B, Ptero- 

 monas angulosa, front and 

 side views ; C and D, P. Cho- 



