NOTES ON THE BRITISH CHARACE^, 1890-1894. 291 



produced at the 2-3 lower nodes, oval, 1-1-1 mm. long, •55--62 

 thick. Nucleus •6d--82 long, •41--4G thick, showing 12 striae. 

 Coronula spreading. Antheridium •40--42 in diameter. Monoecious. 



A medium-sized grey-green plant, of a weak straggling habit, 

 with rather slender stem and branchlets, considerably encrusted. 

 It differs from C. contraria by its cortex being more or less rudi- 

 mentary, but is very closely allied to that species. 



C. denudata was first described by Braun from specimens col- 

 lected at the Cape, and it has since been recorded from Switzerland 

 and Italy. It was discovered in Ireland, in 1892, by Mr. H. C. 

 Levinge, growing in dense masses in about 12 ft. of water in Brittas 

 Lake, Knock Drin, Westmeath. Our description and plate are 

 taken from the Irish plant, which appears to be more extreme than 

 either of the European forms. The Swiss plant from the Lake of 

 Neuchatel, which occurs in GO ft, of water, has a cortex to the stem, 

 but with the primary cells only developed, and has sometimes one 

 or two corticate segments to the branchlets. 



We have received a form of C. contraria, collected by Mr. W. B. 

 Waterfall in the Upper Engadine, which usually has all the seg- 

 ments of the branchlets uucoated, but with here and there 1-2 

 corticate. The fact of C. contraria having a form with entirely 

 uncoated fruiting branchlets and C. denudata having sometimes 

 partially corticate branchlets suggests the question whether the 

 plants included under the latter name are more than extreme forms 

 of the former. We have, however, kept the Irish plant in culti- 

 vation for about a year, and it has retained its distinctive characters, 

 so that we feel bound for the present to retain its specific rank, 



C. denudata is known on the Continent under the later name of 

 C. dissoluta, which was adopted by Braun in his more recent works, 

 because he found that the African plant was not completely ecorti- 

 cate, as he at first thought ; but this is not an allowable reason for 

 rejecting the earlier name, which must therefore stand, 



C. TOMENTOSA, L, — We think the plant collected by Mr. Arthur 

 Bennett in East Norfolk, and recorded in Joiirn. Bot. 1882, p. 86, 

 under this name, is a large state of the supposed hybrid above 

 referred to under C. papulosa. 



C, BispiDA, L,— Bucks, 1882, J. Saunders; Gloster W. & E. (?), 

 •'Canal at Tetbury Road," 1870, W. R. McNab ; Warwick, 1857, 

 T. Kirk; Derby, 1883, J. E. Nowers ; Lake Lanes., 1890, C. Bailey; 

 Kerry N., 1894, D. McArdle; Queen's Co. and Kildare, 1890, R. W. 

 Scully; Dublin, 1893, Armagh, 1892, and Down, 1891, R. LI. 

 Fraeyer; Derry, 1892, M. J. Leebody. 



var. macracantlia . — Dublin, Maynooth, 1890, I>. McArdle. 



var. rudis. — Anglesea, Llyn Wyth Eidol, 1885, J. E. Gtiffith, 

 comm. A. Bennett; Westmeath, Brittas Lake, 1892, H. C. Levinye d- 

 11. iC-J. G. ; Galway W., Arranmore, 1891, S. A. Stewart ; Mayo'W., 

 Ballina, 1891, A. Somerville, comm. A. Bennett ; Armagh, nr. Navan 

 Fort, 1892, R. LI. Praeyer. 



C. VULGARIS, L.— Wilts N., 1893, C.Bailey; Gloster E., 1871, 

 TF, R. McNab; Wigton, 1889, J. Mc Andrew, comm. A. Bennett; 



u 2 



