72 THE JOURNAL OF BOTANY 
himself, as indicated in his description. One thing was certain, 
whatever the affinities of the plant they were not with P. marchica, 
an overlooked plant in districts so well worked as the West Riding 
of Yorkshire, or those divisions of Lancashire so closely investigated 
of late by Messrs. Wheldon and Wilson. The only species open to 
question were P. calcarea and P. fontana, The former has a prima 
Jacie claim to consideration on the ground of its wide cells, and a 
still greater one from the fact that in a certain soft and slender 
form (var. mollis Vent.) it acquires a not indistinct resemblance to 
the plants under discussion. Apart, however, from some structural 
differences, the station of our British P. lawa seems quite sufficient 
to preclude such an origin. P. calcarea is one of our most dis- 
tinctly calcicolous species of moss, while P. fontana is, I believe 
quite as markedly, a calcifuge. In the case of the Crimsworth 
Dean locality, the soil is sand and peat, with no limestone near, 
nor is P. calearea found in the neighbourhood. The Chorley 
locality, Mr. Beesley believes, was probably shale or sandstone, and 
certainly the associates of the Philonotis, viz. Dicranella squarrosa, 
Mnium punctatum, &e., strongly support the supposition of its being 
non-caleareous. Neither P. fontana nor P. calcarea was found 
growing near. 
n my suggestion Mr. Needham made a careful search in the 
neighbourhood of the Crimsworth Dean locality, and found on the 
Yordale shale, within one hundred and fifty yards of the original 
station, two distinct forms of P. fontana, which threw a very 
f 
more slender branches, moreover, the nerve is decidedly narrower, 
the tissue chlorophyllose, and, in 
short, the whole character exactly that of P. laxa, except that the 
nerve 1s usually in some degree stouter, and the leaf apex very 
© proximity of these two plants, clearly referable to P. 
fontana, while at the same time exhibiting characters so unusual 
and so markedly approaching those of the aquatic or subaquatic 
