120 BRITISH CHAROPHYTA. 



tenuior, simplicior et magis composita, laxa et rarius densius 

 contracta et brachyphylla." 



A long interval elapsed after the first discovery of N. gracilis 

 by William Borrer in 1809 and its next collection in 1883. 



The locality for the second record is not known, Mr. Beck- 

 with being unwilling to reveal it, fearing that the plant 

 might be exterminated. Had he been aware of the true 

 nature of the Nitellas the practical impossibility on the one 

 hand of ensuring their permanent growth, and on the other 

 of effecting their extermination he would scarcely have 

 maintained his silence. 



The third English discovery, in Cornwall, is, it will be 

 observed, quite recent, and represents an interesting exten- 

 sion of its known distribution. 



Specimens of a small unidentified Nitella, purporting to 

 have been collected by the late D. Orr, in Grlen Cullen, 

 near Ballybetagh, Co. Dublin, were formerly referred to 

 N. gracilis, but a re-examination shows that they do not 

 belong to this species ; moreover, there is a doubt as to their 

 place of origin. 



8. Nitella tenuissima Kiitzing. 

 (PLATE XIV.) 



Chara tenuissima DESVAUX in Journ. de bot. II, p. 313 (1809). 

 REICHENBACH Iconogr. Bot. t. 791-792, f. 1065-1068 (1830). 

 BRAUN in Flora, XVIII i, p. 53 (1835). 

 GANTERER Oaten*. Char. p. 10, t. 1, f . 1 (1847) pro parte. 

 BABINGTON in Ann. & Mag. Nat. Hist. ser. 2, V, p. 85 (1850). 



C.flexilis var. stellata WALLROTH Ann. Bot. p. 178, t. vi. f. 1-2 (1815). 

 C. stellata S. F. GRAY Nat. AIT. Brit. PI. II, p. 28 (1821). 

 C. exigua BABENHORST in Flora, XX i, p. 131, t. 2 (1837) ? 

 Nitella hyalina AGARDH Syst. Alg. p. 126 (1824) pro parte. 



CURTIS Brit. Entomology, XI, t. 484 (1834). 



VARLEY in Trans. Soc. of Arts, L, p. 186, t. 7, f. 14-19 (1836). 



N. tenuissima KUTZING Phyc. Gen. p. 319 (1843) ; Phyc. Germ. p. 256 



(1845), Sp. Alg. p. 515 (1849) ; Tab. Phyc. VII, t. 34, f. 2 (1857). 

 COSSON & GERMAIN Atl. Fl. Par. t. 41, f.F (1845) ; ed. 2, t. 47 f.G 



(1882). 

 BRAUN in N. Denks. Schweiz. Ges. Naturw. X, p. 10 (1847) ; in 



Monatsb. Akad. Berl. for 1867, p. 887 (1868) ; in Cohn, Krypt. Fl. 



Schles. p. 399 (1876). 



RABENHORST Deutsch. Krypt. Fl. II, p. 196 (1847). 

 WALLMAN Forsok syst. Charac. p. 18 (1853) ; Transl. p. 16 (1856). 

 LEONHARDI in Verh. Naturf. ver. Briinn, p. 169 (1864). 

 WAHLSTEDT Mon. Sver. & Norg. Charac. p. 19 (1875). 

 NORDSTEDT in Bot. Notiser 1863, p. 38; in Flora Danica, t. 2928 



(1877). 



