Wkeldon : The North of England Harpidia. 



7i 



Var. intermedium Schimp. Green or yellowish-green. 

 Stems submersed, elongated, distantly branched, with distant 

 leaves, or shorter with leaves more imbricate. Leaves very 

 variable, sometimes erect, sometimes spreading-, scarcely secund ; 

 the lower lanceolate, the upper oblong-, acuminate. Cells shortly 

 linear, rather longer than in var. polycarpon, and it forms a con- 

 necting link between that and the next group. Marshes, ponds-, 

 and ditches on a sandy or clay soil. 



8. Kirkby-on-Bain, near Woodhall Spa (54), S. C. Stow ! 

 Near Whitwell and Sandacre (57), W. R. Linton ! 



9. Burscough, Ince Blundell, Crossens, Walton, and Kirkby 

 {59), Wheldon ! ! Southport (59), Holt ! Near Bidston (58), 

 Wheldon ! Garstang and Thrang Moss (60), A. Wilson ! 



10. Coatham and Naburn (62), Ingham ! Near Romanby 

 (62), Wheldon ! 



Forma penna Sanio. Yellowish green, rather robust owing 

 to the more dense foliation, tufted, with numerous short pinnate 

 branches. 



9. Warbreck Moor, near Walton (59), Wheldon !•! Pond 

 near Oldham (59), Wheldon ! 



4 Forma laxi folia Ren. (var. laxifolium Sanio). Slender, 

 elongate, with more distant leaves, the apical ones appressed 

 subconvolute, forming a falcate cusp. 



8. Caythorpe (53), S. C. Stow ! 



9. Walton near Liverpool, and Rainford (59), Wheldon ! ! 

 Southport (59), Holt (teste Sanio) ! Hale Moss (58) Holt. 

 Ashton, near Preston (60), H. Beesley ! 



10. Bedale (65), Wheldon ! Coatham (62), Ingham. North- 

 .allerton (62), Wheldon ! 



Group pseudo=fluitans Sanio. 

 (H. aduncum var. laxnm Schimp. in Ren. Rev. Harpid.). 



Robust ; mostly pinnate. Stem leaves distant, erect patent, 

 less heteromorphous than in the preceding group, oblong lance- 

 olate or lanceolate, gradually prolonged into a slender point. 

 Nerve rather long, cells often very long, the enlarged cells of the 

 angles occupying nearly all the leaf-base. The strongly decurrent 

 auricles approach each other, forming between them a small 

 suborbicular sinus. Closely resembling some forms of H. fluitans. 



Var. paternum Sanio. Floating in deep ponds or ditches. 

 Yellowish green, ochreous, or fuscescent. Stems long (10- 

 40 cm.), rigid and robust, or compactly tufted and softer, 

 regularly pinnate or nearly simple. Stem leaves distant below, 



1902 March 3. 



