Wheldon : The North of England Harpidia. 



6 7 



which when quite typical are readily identified, even by eye 

 characters alone. His arrangement, which is followed here with 

 one exception, is an eminently natural one, in which plants are 

 not arbitrarily removed from their nearest associates by a slavish 

 adherence to any single character at the expense of others 

 equally important. In the exception alluded to, I have followed 

 British bryologists in subordinating- Hypnum Wilsoni to H. 

 Sendtneri rather than to H. lycopodioides. In this country at 

 least, the two former appear to be more closely connected. If 

 there is a chain of forms linking H. Wilsoni with H. lycopodioides 

 I cannot avoid the conclusion that the whole of the forms coming 

 under these three names should be united to form an aggregate 

 species, as the segregates do not differ so widely as do forms of 

 II. aduncum and //. fluitans, which are united without question. 

 Most of the following descriptions are based on those of Renauld 

 in 4 Muscologia Gallica,' but I have not hesitated to add to them 

 from the writings of Dr. Braithwaite or Mr. H. N. Dixon, or 

 from my own observation, where there was no doubt of the 

 plants described being identical. In a few instances Mons. 

 Renauld has given names to plants submitted to him which are 

 not defined in his monograph. These I have endeavoured to 

 describe briefly from my specimens, with the aid of his notes on 

 them. Any defects in these descriptions must be attributed to 

 me, but it may be assumed that the plants themselves are 

 correctly referred to the varieties named on Mons. Renauld's 

 authority. 



In the lists of localities a note of exclamation after the col- 

 lector's name indicates that a specimen has passed through my 

 hands. The double sign is intended to imply that Mons. Renauld 

 has seen the specimen and confirmed the name. 



Section I. — Leaves Auricled, Decurrent. 



In ascertaining the presence or absence of auricles great care 

 is necessary. In some species they are difficult to detach with 

 the leaves, but may be seen attached to the stem. In others, 

 really without true auricles, false auricles are formed by the 

 adhesion to the leaf base of portions of the cuticular tissue of the 

 stem. These are carefully figured and described in Renauld's 

 monograph in ' Muscologia Gallica,' and examples may readily 

 be found in H, vernicosum and H. revolvens. 



I. — H. aduncum Hedw. (Ambly 'stegium Kneiffii Schimp. Bry 

 Eur. and of Braithw. Moss Fl.). Very polymorphous. Stems 

 erect or floating, subsimple or vaguely branched, or regularly 



1902 March 3. 



