110 BRITISH CHAliOPHYTA. 



The outer membrane of N. spanioclema exhibits the charac- 

 teristics of N. opaca and N. flexilis as regards the rorid and 

 mottled under- surf ace and the wart-like surface^ but occa- 

 sionally the protuberances are smaller and more prominent. 

 It is however markedly distinguished from the membranes 

 of these two species in that its surface is covered with an 

 exceedingly minute decoration, granular in character and 

 assuming a somewhat net-like disposition. This decoration 

 is not easy to detect in some membranes but is very evident 

 in others. It is observable also on the flanges which, as 

 in the case of N. opaca and N. flexilis, are often con- 

 spicuously developed at the apex of the oospore. 



Section 2. ARTHRODACTYLJE ( = Diarthrodactyl& 

 and Polyarthrodactylae BRAUN). 



Ultimate rays two- or more-celled. 



Subsection 1. Homoeoclemae (= Hom&ophylldel$Ta,im}. 

 Whorls simple, composed of a single circle of similar 

 branchlets. 



5. Nitella translucens Agardh. 

 (PLATE XI.) 



Chara translucens major flexilis VAILLANT Mem. Acad. Roy. Sc., 1719, 



p. 18. t, 3, f. 8. 

 C. flexilis |3, SMITH Fl. Brit. Ill, p. 1384 (1804). 



C-. translucens PERSOON Synopsis, II, p. 531 (1807). 

 SMITH Engl. Bot. No. 1855 (1808). 

 BRAUN in Ann. So. Nat., ser. 2, I. p. 352 (1834) ; in Flora. XVIII. i, 



p. 50 (1835). 

 BABINGTON in Ann. & Mag. Nat. Hist. ser. 2, V, p. 84 (1850). 



C. flexilis THUILLIER FL Par. ed. 2, p. 472 (1799) pro parte, 



Nitella translucens AGARDH Syst. Alg. p. 124 (1824). 



COSSON & GERMAIN Atl. Flor. Par. t. 40, f B (1845) ; ed. 2, t. 46, f.C 



(1882). 



KUTZING Sp. Alg. p. 513 (1849) ; Tab. Phyc. VII, t. 26, f. 1 (1857). 

 PAYER Bot, Crypt, f. 171 (1850). 



WALLMAN Forsok syst, Charac. p. 31 (1853) ; Transl. p. 27 (1856). 

 WAHLSTEDT Bidrag Skand. Charac. p. 2 (1862) ; Mon. Sver. & Norg. 



Charac. p. 17 (1875). 

 NORSTEDT in Bot, Notiser, 1863, p. 36 ; in Flora Danica, No. 2929 



(1877). 



CREPIN in Bull. Soc. Bot. Belg. II. p. 128 (1863). 

 LEONHARDI in Verb. Naturf. ver. Briinn. II, p. 173 (1864). 

 BRAUN in Monatsb. Akad. Bevl. for 1867, p. 879 (1868). 

 GROVES in Journ. Bot. XVIII. p. 165. t. 210, f. 17 (1880). 



