MOSSES 23 



hand, will often furnish many specimens for the 

 collector, such as the Great Hairy Screw-moss 

 (Tortula ruralis], a near relative of the Common 

 Wall Screw-moss ( Tortula muralis) ; certain forms 

 of the Cypress-leaved Feather-moss (Hypnum 

 cupressiforme), one of the commonest of our 

 Eeather-mosses ; and the Bent-leaved Didymodon 

 (Didymodon flexifolius), so called because its 

 leaves are somewhat bent back (squarrose), as will 

 be seen on reference to Plate VII. fig. 33 where a 

 magnified drawing of one is given. 



Not only do we find that, roughly speaking, 

 certain mosses have a natural predilection for a 

 special form of habitation, but further, that some 

 are attracted by the geological character of some 

 particular locality. Thus, many most interesting 

 kinds abound in limestone districts, such as Dove 

 Dale and Miller's Dale, in Derbyshire, for which 

 we should search in vain in a non-calcareous 

 region. Plate II. fig. 15 is a drawing of a small 

 yellowish-green moss, the Curly-leaved Screw- 

 moss (Trichostomum tortuosum), which is com- 

 paratively seldom met with except on limestone 

 rocks ; it has long fragile leaves, which, when 

 dry, are strongly twisted or contorted to which 

 fact, no doubt, it owes its specific name. An 

 enlarged drawing of one of these leaves, showing 

 its peculiarly wavy margin, is given at Plate 

 VII. fig. 32. The Crisped Neckera (Neckera 

 crispa), with its delicate undulated leaves and 



