THE BRYOPHYTA OF ICELAND 453 



both on rocks and on earth. In lava-fields it is one of the most com- 

 monh' occurring species, and grows there in enormous cushions on 

 rock-sides in caves and clefts, in association with Amphidium Moiigottii, 

 AmvcUinyiam compacinm and Grimmid lorqiiaUi. On rocks it grows 

 on perpendicular faces, on soil-covered ledges, and in clefts. On the 

 ground it is found especially where it is not too damp, for instance in 

 grass-fields and on the top of knoils in bogs, usiially intermixed in tufts 

 of other mosses. At higher altitudes it rarel}' grows on rocks, but as 

 a rule on gravelly ground or in bogs. Only sterile speciniens have been 

 found. 



This species varies considerably in the size and length of the 

 leaves. Forms from shady and protected localities, especially from 

 lava-clefts, form very tall and loose tufts with exceedingly long and 

 strongly crisped leaves. 



61. Tortella fragilis (Drumm.) Limpr. 

 Mollia frufjilis (Drumm.) Lindb. 



Commonl}' distributed all over Iceland. 



This species grows in localities similar to those of T. tortuosa, and 

 often in company with the latter, but as a rule rather scantily. It 

 usually occurs in unmixed tufts on soil-covered rocks and on some- 

 what damp ground, but only sterile specimens have been found. Around 

 Reykjavik, for instance, it was common on knoils in bogg}' tracts which 

 had been partially drained. In NW. Iceland it is rather rare, and has 

 only been found in a few localities near Kaldalon. 



62. Barbula unguiculata (Huds.) Hedw. 



var. ctispidata (Schultz) Braithw. 



S. Iceland: Vestmannaey !, on damp gravelly soil near the town. It 

 has previously been collected here b}' an unknown finder H.Jonsson 

 believes by G. Bry nj olfs en). \V. Iceland : Saurbær near Hvalljordur, 

 at an attitude of about 100 metres, on soil-covered rocks. In both 

 piaces only sterile specimens have been found. 



63. Barbula fallax (Hedw.). 



S. Iceland: Reykir ^. W. Iceland: Saudlauksdalur (H. J.). 



Var. lævifolia n. var. 



In wide dense cushions, 2—3 inches deep, rusty brown in the in- 

 terior, brownish green at the top. The lower leaves as in the type, the 

 uppermost shortly pointed with rounded, broad and flat apex, into 

 which the strong nerve runs out, widely revolute to near apex, with 

 two deep plicæ at the base. Leaf-cells in form and size as in B. fallax, 

 in the lower half of the uppermost leaves, however, more thin-walled, 

 shortly rectangular; all quite smooth or, more rarely, indistincth' papil- 

 lose. The innermost perichætial leaves ovate or widely lanceolate, with 

 faint or indistinct nerves. 



