96 BRITISH CHAKOPHYTA. 



from the simplest form with few similar once-forked 

 branchlets and 1-celled secondary rays, to complex 

 types, (1) with numerous branchlets of differing 

 forms, (2) with repeatedly forked branchlets often 

 partially monopodial in growth, and (3) with the 

 ultimate rays many-celled. 



J V 



The terminal position of the antheridium is the most 

 important distinctive character of the genus. The 

 laterally-compressed oospore seems also to be pecu- 

 liar to the genus, and affords an important distinc- 

 tion which does not appear to have been hitherto 

 recognized. 



The stem and branchlets are usuallv of a clear 



d 



translucent green colour, and, owing to the absence 

 of cortex, and the small extent to which they become 

 incrusted with lime, are more flexible than in most 

 of the species belonging to the other genera. The 

 incrustation when present is almost always annular 

 in character, the bands being approximately of the 

 same width as the spaces between them. We have 

 not met with any explanation of the cause of this 

 phenomenon, which is apparently peculiar to the 

 genus. The known species number about 100, dis- 

 tributed throughout the world. 



Section 1. ANAETHEOLAGTYL^ ( = Monartkro- 



dadylse BRAUN). 



Ultimate rays one-celled. 



t/ 



1. Nitella capillaris comb. nor. 

 (PLATE VI.) 



Chant capillaris KROCKER Fl. Siles. Ill, p. 62 (1814). 



C. capitata NEES in Denks. Buier bot. Ges. II, p. 80, t. 6 (1818). 



BRUZELIUS Obs. o-en. Charge, p. 24 (1824). 



BRAUN in Ann. So. Nat. ser. 2, I, p. 352 (1834). 

 C. elastica AMICI in Mem. Accad. Modem, I, p. 205, t, 1-2 (1827). 

 C. glomerata BISCHOFF Krypt. Gew. t. 1, f. 6, 8 (1828) non Desv. 

 C. syncarpa REICHENBACH Iconogr. Bot. pro parte, f. 1076-7 (1830) ? 

 C. syncarpa var. capitata GANTERER Osterr. Char. p. 9 (1847). 



