Protococcacece 237 



Schmidle 1 gave what he termed an 'amended description' of 

 this genus in 1894, but as the plant he included in it is not a 

 species of Tetracoccus, his amended description is not a correct 

 one 2 . 



T. botryoides West is widely distributed in the British Islands, generally 

 occurring in the surface waters of ponds and in the plankton of large lakes. 

 Diam. of cells 3'8 57 /* ; diam. of colonies 30 57 /*; fig. 105. 



Genus Botryococcus Kiitz., 1849. The colony is free-floating 

 and consists of an aggregate of botryoidal groups of cells. The 

 cells are globose or ovoid in form 

 and are closely aggregated to form 

 clusters of 16 or 32 cells, the clusters 

 being held together partly by old 

 mother-cell-walls and partly by a 

 gelatinous investment. There is a 

 single cup-shaped chloroplast in each 

 cell, but pyrenoids have not been 

 observed, Chodat and Cretier 3 have Braunii Kiitz'., 



observed in the chloroplast a Small Forest, Hants. A, small colony; 

 r i i i , B, two isolated cells ( x 450). 



body which can be regarded as a 



pyrenoid without an amylosphere. As a rule this Alga is of a 

 bright green colour, but when occurring in large quantity, as it 

 frequently does in the freshwater plankton, the cells become filled 

 with a brick-red oil. 



B. Braunii Kiitz. is the best known representative of the genus, and is a 

 frequent plant in bog-pools, large ponds, lakes, etc. Diam. of cells 5'5 9 p. ; 

 tig. 106. B. sudeticus Lemm. (which may only be a form of B. Braunii with 

 globose cells) and B. calcarem West are rarer British species. 



Genus Ineffigiata West & G. S. West, 1897; em. 1903. 

 This Alga consists of free-floating colonies of very irregular form 

 and destitute of a gelatinous investment. The colony is composed 

 of several families of cells agglutinated together, each family 

 being small, more or less spherical, and consisting of a peripheral 

 layer of cells surrounding a central cavity. The cells are ellipsoid 

 or ovoid in form, and each one is furnished with a parietal chloro- 

 plast, often containing what has been described as a single small 



1 Schmidle in Flora, 1894, Heft 1, p. 45. 



' 2 Vide West & G. S. West iu Journ. Eoy. Micr. Soc. 1896, p. 162. 



3 Chodat & Cretier in Arch. Sci. Phys. et Nat. x, 1900. 



