BRITISH CHAROPHYTA. 



CHARES. 



Leonhaedi in Lotos, XIII, p. 72 (1863). 

 Charse pleurogynse et hypogynse Braun in Ann. Sc. Nat. 

 ser. 2, I, p. 353 (1834). 



Stem and branclilets with or without cortex. Bran- 

 ches normally one at a stem-node. Branchlets simple, 

 producing bract-cells at their nodes. Coronula of 

 oogonium composed of 5 cells in one tier. Oospore 

 terete. Antheridium lateral. 



The important character distinguishing this division of the 

 group from the Nitellese consists in the construction of the 

 coronula formed of five cells only, arranged in a single tier. The 

 oogonium and oospore are never laterally compressed. In a 

 considerable number of the species the oogonium develops a 

 lime-shell, the production of which in the Nitellese is confined 

 to the genus Tolypella. With the exception of Nitellopsis, all 

 the species produce at the base of the branchlets one or two 

 rings of cells, usually small, and in most cases more or less 

 elongated, the stipulodes, which are absent in the Nitelleae. The 

 segments of the branchlets always exhibit a sympodial arrange- 

 ment. 



A reference to the plates illustrating the marking of the 

 membranes will show that all the British Chareae possess either 

 a granulate or a tuberculate decoration of the oospore, and that in 

 many cases the decorations are so much alike in the various 

 species as scarcely to be distinguished. In some fruits of a plant 

 the markings are obscure and dif&cult to determine, while in 

 other fruits of the same plant they are clear and well defined. 

 The markings show themselves most conspicuously within the 

 pentagonal base of the oospore ; here in many instances the 

 characters of the decoration, which cannot well be determined in 



VOL. II. 1 



