THE BRYOPHYTA OF ICELAND 423 



73. Anthelia julacea (L.) Dum. 



Common in the lowlands on damp gravelly ground and creeping 

 over wet stones in streams, occasionally also on damp boggy soil; fruit 

 is not rare. It does not appear to ascend higher than about 400 me- 

 tres above sea-level. 



74. Anthelia Juratzkana (Limpr.) Trevis. 

 Anthelia nivalis (S\v.) Limpr. ex. p. 



Very common on damp gravelly flåts irrigated by melting snow, 

 somewhat rarer on damp gravelly ground along streams or on damp 

 rocks. 



This plant has its main distribution on mountain heights where, 

 on the clayey or gravelly flåts ne.Kt to the snow-covered areas, it forms 

 large, continuous carpets of a peculiar bluish-black colour. often mixed 

 w'ith Salix herbacea or with other Bryophyta such as Alicularia geo- 

 scypha. Lophozia ventricosa and Polytrichum sexangulare. In NW. Ice- 

 land, where the snow on slopes with a northern exposure mav remain 

 during the greater part of the summer, Ihese Anthelieta often descend 

 to sea-level. The piants growing on damp rocks or gravelly ground in 

 lower levels differ from the typical form from mountain heights in being 

 lighter in colour, usually yellowlsh green, and in the tufts being as a 

 rule higher, with less close-set leaves; or it may also grow intermixed 

 with other Bryophyta especially Hepaticæ. 



A. Juratzkana and A. nivalis are so closely related that in many 

 cases it is impossible to determine them when sterile. While the typi- 

 cal A. Juratzkana, as it occurs in abundance on mountain heights, is 

 very characteristic because of its extensive low carpets, quite typical 

 speciniens of A. julacea are far more rarely met with on the damp soil 

 of the lowlands. Of far more frequent occurrence are forms which 

 pass, more or less, in habit, size of leaf-cells and thickness of cell-walls 

 from A. julacea towards A. Juratzkana. 



75. Ptilidium ciliare (L.) Hampe. 



Very common both on dry and on somewhat damp ground. 



The plant grows both among Hylocomium spp. on slopes and inter- 

 mixed in heaths of Rhacomitruun hypnoides and R. canescens on more 

 or less damp rocks coated with soil, and also in clefts in lava-fields 

 and on knolis in bogs. It occurs most frequently in low-lying regions 

 up to about 300—400 metres, but may also occasionally be met with 

 on mountain heights. Only sterile specimens have been found. 



Fam. SCAPANIOIDEÆ. 

 76. Diplophyllum albicans (L.) Dum. 



"In Islandia" (Morch!). W. Iceland: Budahraun i^H.J.V; Hafnarfjordur 

 (Grl.; H. J.;!); Svinahraun!; Modruvellir in Kjos!. S. Iceland: Thingvalla- 



