i899-J Johnson". — The Irish Char acece. 151 



II. Dkecious. 



Tolypellopsis (v. Leonh.) Migula. 



(This genus includes Lycnothamnus stelliger, Braun, not yet recorded for 

 Ireland). 



Cortex of stem and leaves and stipular whorl absent. In place of 

 stipules 3 small cells of the basal node of the leaf are strongly developed 

 on the outer side of the leaf at its base. 



Leaves with only one or two nodes, leaflets one or two at the nodes, 

 often quite absent. 



Antheridia and oogonia represent leaflets ; antheridia are solitary, 

 stalked, quite at the bulging side of the leaf. Oogonia solitary or in pairs 

 with quite short, often a common stalk cell, on the bulging part of the 

 leaf. 



The neck portion of the involucre cells is elongated and beaklike ; 

 the corona is small, rounded off with small cells, not erect, and becoming 

 thinner towards the apex. 

 Tolypellopsis is distinguished 



a. from all other Charecs by the absence of a stipular whorl, the form of 



the involucre-cells and of the corona, as well as in habit by the 

 small number of leaflets. 



b. from Lycnothamnus by the position of the antheridia, 



c. from Lamprothamnus by the development of the oogonia. 



d. from Cham, by this and by the completely^different structure of the 



stem node. 

 {Lamprothamnus aiopecuroides, Braun. is very rare, not recorded for 

 Ireland ; it was discovered in the Isle of Wight, in 1862, by the late A. G. 

 More, and is recognisable by the characters of the genus already given."] 



REVIEW OF SPECIES OF CHARA. 

 I. Whorl of stipules i-seriate, plants monoecious : 



Haplostcphana, A. Br. 

 Completely uncortexed, oospore or nucule without a chalky 

 envelope or involucre. End-joint of leaves a little longer than 

 the leaflets of the last node and producing with these mostly 

 a 3 -pointed crown or tuft. [23. C. coronata Ziz. or C- 



Braunii, Gruel.] 

 II. Whorl of stipules biseriate (in C. ceralophylla sometimes tri- 

 seriate). 

 Plants monoecious or dioecious : Diplostephana, A. Br. 



A. Cortex incomplete, only -of elongated, irregular cells : 



Imperfecta, A. Br, [25. C. imperfecta.^ 



B. Stem cortex complete, of elongated internodal cells and 

 isodiametric nodal cells : Ferfcctie, A. Br. 



1. Number of rows of cortical cells same as of leaves of 

 corresponding node : Isosiicfuc A. Br. 



* Dioecious. 26. C. crinita Wallr. 



or C. canesce/:s, Loisel. 



* Monoecious. 27. C. denudata, A. Br. 



or C. d/sso/ula, A. Br. 



