AR 
90 jeu REVUE BRYOLOGIQUE 
of the calciphilous, arenophilous, and halophilous associations. 
The harpidia oceur in the richest profusion, all our British species 
being found except Æ. uncinalum, H. fluitans, H. exannulatum, 
and 1. vernicosum. — Hypnum aduncum is represented chiefly 
by the groups pseudofluitans and typicum, which occur pentifully, 
in pure growths, or in mixture with each other, or with other 
_Harpidia and aquatic mosses. The forms of group Kneiffii are 
much rarer, and appear to be confined Lo one or two places, in 
_ one of them mixed with group typicum. This free mixing ofthe 
various groups Of 77. aduncum under identical conditions of envi- 
ronment seems to imply that their peculiarities are not due to 
those conditions but are more or less fixed and permanent, 
sufficiently so to prevent Uhem reverting to one common type 
when subjected to the same local influences. As the better marked 
forms appear to have a wide distribution also, both, in Great 
Britain and on the continent, their stability must be admitted. 
For these reasons, and also for the sake of brevity in referring 
to the forms, Herr Warnstorfs action in assigning the rank of 
species Lo some of the better marked. varieties recognised by 
Renauld is to be commended. If the grade of « subspecies » is to 
be recognised, these forms seem however Lo merit this designa- 
tion rather than such distinct species as 4. lycopodioides and 
H. Stendineri. à 
 HYPNUM SENDTNERI Schimp. — This species is regarded by some 
authorities as an alpine form or subspecies of 4. aduncum, and 
according to Mess" Langeron and Renauld, on the continent, it is 
distributed at greater altitudes than that species. In Great Britain, 
on the contrary, the range of the two plants appears to be iden- 
tical. 1 have never seen a specimen of either collected at above 
300 feet altitude, If 4. Sendtneri occurs in our mountains, the 
localities must be few, as I have received large gatherings of 
Harpidia from most of the ranges of England, Scotland and 
= Ireland without meeting with an example. I have also searched 
for it myself in the hilly districts of Scotland, Westmorland, 
= Yorkshire and Lancashire, without success. The localities from 
which most of specimens come are near the sea coast, and it 
appears Lo become rarer inland. In {he neighbourhood of Liverpool, 
it occurs inland near Rainford and Burscough, and was no doubt 
formerly abundant on the extensive marshes of the western 
portion of South Lancashire. M. Travis has found well preserved 
fossil examples, associated with Æ{ypnum scorpioides, in peat 
= bands underlying the Upper Shirdley Drift Sand near Walton. 
Our inland plant shows no tendency to approach 4. Wilsoni in 
CL 
