MOSS HABITATS. 91 
Didymodon rubellus, so far as my own observations serve, is some- 
what local; is usually fond of old shady walls; and fruits from 
November to February. Grows in dull green tufts, which are reddish 
“below ; the leaves lance-shaped, somewhat clasping the stem at their 
base; margins recurved; leaf-cells minute in upper part, towards the 
base elongated and transparent. The leaves, too, are spreading when 
moist, but twisted when dry ; the capsule is cylindrical ; fringe of sixteen 
simple teeth ; lid slightly curved and beaked. 
Pottia lanceolata I have usually found abundantly on the mud- 
capped walls in the Lias districts of South Warwickshire; growing in 
rather loose dark green patches, often of great extent. The leaves are 
variable in size and form, generally oval-oblong, tapering, with longish 
green points; and slightly keeled on the back. Leaf-cells rather large, 
quadrate above, longer and transparent below; capsule erect; fringe of 
sixteen teeth ; lid beaked. 
A true bryologist should never be afraid of damp and dirty boots; 
if he be, I am afraid he will scarcely care to follow me to the habitats I 
have next to mention, that is, the marshes and bogs, and will thereby 
lose some of the rarest and most beautiful of the mosses. The odours 
of a marsh are not always of so grateful a nature as one would desire for 
a bouquet, but the gems which cluster round its margin, or more boldly 
brave its deeper depths, are worthy to be placed among the fairest of the 
floral world, and speak as loudly of the marvellous skill of the Great 
Designer, as the most beautiful and complicate of God’s creatures. He 
who doubts this should examine with the microscope the wonderful 
structure of a Sphagnum leaf; and ifthe delicate network that he will 
then haye revealed fail to charm, it will be because his power of appre- 
ciating beautiful objects is limited. Among other denizens of these 
watery situations he will find the Sphagnums most abundant, and such 
mosses as Bartramia fontana, Mnium subglobosum, Hypnum cuspidatum, 
Aulacomnion palustre, and many other species, which space will not 
permit me to name. 
Many species of Sphagnum will be found in these habitats, but the 
species I find most widely diffused is Sphagnum cymbifolium. This often 
forms extensive masses, of a pale green colour, and may readily be known 
from the other species by the obtuse leaves, and by the elongated cells 
which coat both stem and branches, (the utricles,) being lined with spiral 
threads. 
Bartramia fontana is a frequent denizen of our Warwickshire marshes, 
but rarely in fruit. It occursin more or less dense tufts of a glaucous 
green colour, and has the stems much matted together by reddish 
rootlets ; the leaves are mostly ovate, with a prolonged point, have 
reflexed margins, and are slightly plicate at the base; the cells are 
small and quadrate; the leaf-margin bluntly toothed; the capsule is 
roundish, curved, marked with deep longitudinal furrows, and reddish- 
brown when ripe ; fringe double; lid convex. 
Mnium subglobosum is a more local moss, but abundant in some 
marshes, occurring in dark-green tufts. The leaves are large, roundish, 
