THK BRYOPHYTA OF ICELAND 587 



Of other species the following were observed: Pohlia nulans, P. 

 crnda, Brynm ccespiticium, B. affine, Bartramia ityphylla, Poly trie hum 

 alpinum, P. jumperiniim, Distichium montanum, Ditrichum flexicaule, 

 Scelania ccesia, Tortnla snbulata, T. rnralis, Dicranum scoparium, 

 Ptilidium ciliare, Lophozia lycopodioides, L. qainquedentata, Fnillama 

 Tamarisci and Scapania curta. 



Birch coppice in Kaldalon (NW. Iceland). The south-west- 

 ern slope was covered with a low-growing and very dense birch 

 coppice with a ground vegetation of numerous flowering plants 

 (Geranium silvaticum, Bartsia alpina, Taraxacum, etc.) and a Bryo- 

 phytc carpet of Hijlocomium proliferum, H. parietinum, H. squarrosum 

 and Hypnum uncmatum intermixed with Dicranum scoparium, D. 

 fuscescens, Pogonalum urnigerum, Pohjtrichnm alpinum, Lophozia hj- 

 copodioides, L. quinquedentata, L.Floerckei, L. ventricosa , Cephalozia 

 bicuspidata and C. pleniceps. In open spots Pohlia nutans was very 

 common, and Polyfrichum gracile occurred frequently on knolls on 

 the floor of the coppice. 



Of a similar composition is the moss carpet of all the coppices 

 of NW. Iceland. In several spots Dicranum majus and Hijlocomium 

 triquetrum also occurred. 



Bryophyta of Soil recently laid bare. On slopes, on 

 the sides of clefts, on soil covered rock-ledges and, on the whole, 

 in all places where by weathering, by land-slips or by the action 

 of water new soil is produced, which has not yet become inhabited 

 by higher plants, a luxuriant Bryophyte vegetation occurs, which 

 C.Jensen (1910, p. 258) includes in a group within the mesophi- 

 lous associations, under the name "Moosvereine des frischen Erd- 

 bodens". A number of species are here met with, especially of the 

 commonly occurring mesophilous forms, but also, several species 

 belonging to damp sandy soil and to rocks. It is especially liver- 

 worts and the acrocarpous mosses which are represented here, 

 while the pleurocarpous mosses occur but scantily. It is a con- 

 dition for the growth of mosses that there is an abundant snow- 

 covering during winter, which affords them protection from de- 

 siccation by wind. 



The composition of the moss-covering varies greatly according 

 to the prevailing degree of humidity, and the local conditions. 



In such localities as those mentioned above the following 

 Hepaticre occur: Anenra pinguis, Marchantia polymorpha, Gijm- 

 uomitriiim coucinnatum , Alicularia scalaris, A. geoscypha, Lophozia 



38* 



