THE BRYOPHYTA OF ICELAND 451 



country, wherc il is common in many piaces and often occurs in 

 enormous quantities. Morch records that it grows in lioles in the 

 lava. Near Kolvidarhol it was found everywhcre on tutf, from the 

 larm (at about 250 metres) up to about 150 metres above sea-level; it 

 was found in extensive mats, especiallj' on the vertical or overhanging 

 sides of the tumbled-down blocks, and in the interior of holes and 

 clefts. It was most frequent on Fljotshlid and south of Flyjafjall. 

 There it was growing in many piaces on the vertical sides of tuff-rocks 

 in the ravines and on the fallen blocks, for instance in Flokastadagil 

 near Breidabolstadr it covered long stretches of the perpendicular sides 

 of a ravine, from a distance of a few cm. above the water-level of the 

 river upw^ards, with a dark-green closely adhering mat in which almost 

 no other mosses were intermixed. In this part of the countrj^ it has 

 only been met with up to about 100 metres above sea-level. Only ste- 

 rile specimens have been found. 



Bnjoxiphium noroegiciim is the only Iceland moss which does not 

 occur on the European continent or in the British Isles. Outside Ice- 

 land it has only been known to occur in a few localities in North 

 America (Ohio, Kentucky and Wisconsin). 



Fam. POTTIACEÆ. 



53. Pottia Heimii (^Hedw.) Br. eur. 



Iceland (Morch)! 



E. Iceland: Hornafjordur!. N. Iceland: near Ej^jafjordur (F.)!; 

 Saudanes (St.)!; Grimsey (O. D.)!. NW. Iceland: Armuli!. W. Iceland: 

 Reykjavik (Grl.;!); Borgarnes!. S. Iceland: Vestmannaey !. 



This species grows on sandy or muddj' soil near the sea, and is 

 probably commonh' distributed along the whole coast in such localities. 

 Around Reykjavik, on Vestmannaey and near Hornafjårdur it was com- 

 mon, and was frequently found also on soil-covered rocks and in rock- 

 clefts close to the sea. 



The fruit ripens about July Ist; on Grimsey the fruit was fulW 

 ripe on July 14th, but the lids had not been thrown off. Near Armuli 

 it was hardly ripe during the flrst days of July. 



54. Pottia latifolia (Schwågr.) C. M. 



N. Iceland: Hof near EyjaQordur (O. D.)!; Os (O. D.)!, with ripe 

 capsules on June 17th. 



Note. Pottia triincatiila and P. lanceolata are enumerated in older 

 lists as found in Iceland, but no specimens of these species are to be 

 found in the collections, and their occurrence in Iceland is very im- 

 probable. 



55. Didomodon rubellus (Hoffm). Br. eur. 



Barbala nibella .Hoffm.) Mitten. 



Very common everywhere on a more or a less damp substratum, 

 in rock-clefts, on the ground, on rocks and gravellj' soil by rivers, in 

 bogs, etc. It grows sometimes in unmixed tufts and sometimes inter- 



