char ace.*:. 187 



Yar. a recorded from Devonshire, Hay ling Island, Hants ; Kent, 

 Middlesex, Essex, Norfolk, Cambridgeshire, Lancashire, Huntingdon- 

 shire, Yorkshire, Anglesea, Forfarshire, and near Dublin. Originally 

 found near Cley, Norfolk, by Mr. Dawson Turner, and Mr. Borrer, in 

 1806. Yar. j3 at Lancing, Sussex, in 1804-5, by Mr. Borrer, who 

 says [Suppl. to Engl. Bot. 1834, Yol. II., under No. 2762] it was 

 found in a ditch " which I believe the tide never reaches." 



England, Wales, Scotland, and Ireland. Annual, perennial. 

 Spring, early Summer. 



Stems much branched, very brittle, light or dark olive, and trans- 

 parent when not coated with carbonate of lime, as is generally the 

 case, 3 inches to 1 foot long ; barren branchlets § to 2 inches long. 

 Fertile heads about J inch long by ^ inch across. [The nucules 

 sometimes have the spiral investing cells prolonged above the nucleus 

 or nut, into a short neck, as shewn in one of the nucules on our 

 plate (1905), which was taken from the more robust specimen thereon 

 represented, all the nucules of that plant being similar.] 



Messrs. H. and J. Groves and MM. Cosson and Germain both cite 

 No. L7 Braun, Babenh. and Stiz. Char. Europ. Exsicc. But in my set 

 No. 17 is Nitella mucronata var. tenuior, and there is no N. glome- 

 rata in the set at all. [This seems to be the case in some other sets.] 



With regard to the plant called C. Smithii by Babington, the 

 question of its identity with the ordinary form of N. glomerata 

 must remain uncertain ; all the other known species of the section 

 Tolvpella are monoecious, so it would be a curious circumstance if 

 N. Smithii were really dioecious ; yet Mr. Borrer was far too acute an 

 observer, and far too correct, to be likely to make a mistake on the 

 point. [I have very carefully examined Mr. Borrer's Lancing speci- 

 men, and only find globules upon it, not a trace of a nucule : this is 

 therefore, I have no doubt, another case of a polygamous species, as 

 in that of N. flexilis ; see note under N. syncarpa var. opaca. — 

 X. E. B.] 



Clustered Xitella. 



SPECIES YJII.-N ITELLA INTRICATA. Agardh. 



Plate 1907 asd 1908. 



Monoecious. Very pale olive. Stem rather stout, transparent or more 

 commonly opaque from being thickly encrusted with carbonate of lime, 

 without cortical cells or spine-cells or stipule-cells. Branchlets 6 to 20 

 in a whorl ; those of the primary whorls sterile, of 3 to 5 cells, acute, 

 usually with a few simple or once-branched, 3- or 4-jointed branchlets 



