6 BRITISH CHAROPHYTA. 



as the fruit matures, the posterior wall remaining distinct from 

 the membrane of the oospore, while the lateral walls form 

 between the cells what appears to be an extended flange to the 

 ridges. When the whole integument is removed the oospore 

 exhibits sharp low ridges. 



There is an element of doubt as to the status of the plant in 

 the Surrey locaHty, other water plants having appeared suddenly 

 in the pool below Walton Bridge, suggesting the possibihty of 

 intentional introduction. 



It is with regret that we have been obliged to surrender the 

 very appropriate specific name stelligera, by which the plant is 

 generally known, in favour of the first of the two earlier names. 



[Lychnothamnus barbatus Leonhardi, having an 

 imperfect haplostichous stem-cortex, ecorticate few- 

 segmented branchlets, long stipulodes, and oogonia and 

 antheridia situated side by side, arising from different 

 peripheral cells of the branchlet-node, one oogonium 

 usually between two antheridia, has been found in a 

 few localities in France, Germany, Italy, and India.] 



Genus 2. LAMPROTHAMNIUM J. Groves. 



Lamprothamnus Beatjn in Braun & Nordstedt, Fragm. Mon. Oharac. 



pp. 16 & 100 (1882), non Hiern. 

 Lamprothamnium J. Geoves in Journ. Bot. LIV, p. 336 (1916). 



Stem and branchlets ecorticate. Stipulodes present. 

 Oogonium normally situated below the antheridium, 

 both arising from the central anterior peripheral cell 

 of the branchlet-node. 



A small genus occurring in the Western half of Europe and 

 in North- Western and Southern Africa, in brackish water, 

 usually quite near the coast. The relative position of the 

 reproductive organs, which is the reverse of that found in Chara, 

 serves to distinguish it from that genus, to which it is closely 

 allied. Species described, four.* 



* Lamprothamnus montevideensis Spegazzini does not appear, from the 

 author's description, to belong to this genus. 



