MOSS HABITATS. 



37 



the ash, has a creeping pinnate stem, fruiting branches erect, 

 the capsule immersed in the sur- 

 rounding leaves, the calyptra 

 conical, brownish, and the fringe 

 or peristome white. Fruiting in 

 June. 



Leucodon sriuroides I find upon 

 the ash, elm, and apple trees, 

 often very abundant, but very 

 rarely fruiting. This species has 

 also a creeping stem, with nu- 

 merous erect shoots ; the leaves 

 are spreading when moist, but 

 imbricate (overlapping) when 

 dry; the shoots are thickened 

 at the end and incurved, and 

 the leaves are nerveless; mar- 

 ginal leaf-cells round, central 

 ones oblong. 



In calcareous and marly soils 

 I find the yellowish-green tufts 

 of Zygodon viridissimus (fig. 20, 

 central figure) not unfrequently 

 on the lower part of the trunks 

 of elm, ash, and sometimes oak 

 trees ; when moist and fresh- 

 gathered the leaves are spread- 

 ing, but when dry they are 

 crisped and somewhat twisted; 

 the leaves are widely lance- 

 shaped, have plane margins, 

 very small dot-like cells, and a 

 pellucid nerve. I have not seen 

 this in fruit, but it should be 

 sought for in spring. 



Weissia cirrhata is an abun- 2 ' ***** ****** 

 dant moss on trees, gate-posts, 



and rails, forming dark-green cushions. The leaves are 

 lanceolate, with the margins turned over towards the under- 



FIG. 21. i, Mnium undulatum. 



