A REVIEW OF THE BRITISH CHARACEjE. 163 



large densely compound heads ; brancLlets divided into 3-4 acute, 

 2-3-, rarely 4-, celled rays. Nucules globosely ovoid. (Tab. 209, 

 f. 12). 



A very large plant, of which our figure is a reduced represent- 

 ation. The sterile branchlets are sometimes 7 in. long and very 

 stout. It is a rare species, and has only been found in a few 

 scattered localities in Central and Southern Europe. It was 

 discovered in Britain by Mr. Borrer in 1827, near Rye Farm, 

 Henfield, Sussex, and has since been found by Dr. Moore in the 

 canal near Glasnevin, Dublin. 



ni. T. intricata, Leonh. Lotos, 1863 (name) ; Braun, in Cohn's 

 Krypt. Flor. von Schlesien (1877), p. 400. 



Chara intricata, Roth. Catalecta Botanica (1800), fas. ii., p. 125. 



Nitella intricata, Auct. (Ag. ?) ; Braun, Consp. Char. Europ., 

 p. 3; Fl. Dan. (1867), t. 2744; Braun, R. & S. Exs. 18, 33, 108; 

 Nordst. & Wahlst. Exs. 46, 48. 



Chara fasciexdata , Amici, Descriz. di alcune sp. nuove di Chara 

 (1827), p.* 16, t. 4, f. 4, and t. 5, f. 3. 



Chara polysperma, Braun, Ann. Sc. Nat., 1834, p. 352; Gant. 

 Oesterr. Char. (1847), p. 12, t. 1, f. 3; Bab. A. N. H., v. (1850), 

 p. 88; Wallm. Act. Stockh., 1854, p. 269. 



Nitella poly sper ma, Kiitz. Phyc. Gen. (1843), p. 318. 



N. fasciculata, Braun, Schweiz. Char., p. 11 ; Kiitz. Tab. Phyc, 

 vh., t. 36, f. 1. 



Stem moderately stout. Sterile whorls of 6-10 once or twice 

 divided branchlets ; rays unequal, the ultimate acute, 3-5-celled. 

 Fertile whorls in very large dense compound heads ; branchlets 

 once or twice divided, ultimate rays 4-5 celled, acute. Nucules 

 numerous, globosely ovoid, stalked or sessile, 8-9-striate. (Tab. 

 209, f. 13.) 



Distinguished from both the preceding species by its divided 

 branchlets. It is widely distributed in Europe, and extends to 

 North Africa. In Britain it is very rare, and does not appear to 

 have been found for two successive years in any locality ; there is 

 a specimen in Herb. Buddie, but no locality is given. 



Ponds, pools, and canals. April and May. Essex, N. ; 

 Suffolk, W. ; Cambridge; Yorksh., N. (DaltonV, Durham; 

 Dublin. 



4.— NITELLA. 



Ag. Syst. Alg. (1824), Introd., p. 27, ex parte. 



Stem rarely producing more than 2 branches at each node. 

 Branchlets simple, or 1-4 times divided into nearly equal rays. 

 Globules in the forking of the branchlets, thus terminating the 

 segment from the apex of which the forking arises. Nucules below 

 "ie globules, lateral. Monoecious or dioecious. 



§ Ultimate rays of 2 or more cells. 



I. N. tenuissima, Kiitz. Phyc. Gen. (1843), p. 819 ; Coss. & 

 Germ. Atl. Fl. Par., t. 41 ; Wallm. Act. Stockh., 1854 ; Kiitz. 



