THE BRYOPHYTA OF ICELAXD 52/ 



to a very long and slender point, and are about 1 mm. long and 0.4 mm. 

 broad. The branch leavcs are lanceolale and toothcd along their entire 

 margin, with short nerve. The cells at the base of the leaf are quadrate. 

 yellow and rather thick-walled, 0.012—0.015 mm. broad; those in the 

 upper half of the leaf narrowh' prosenchymatous, 0.08 mm. broad, and 

 6—8 times as long, and often somewhat wav}'. 



278. Siibsp. * Amblystegium littorale (C.Jens.) Hesselbo. 

 Syn. A mb ly steg in m serpens var. litloralis C. Jens. in "Færoernes Mosser". 



N. Iceland: Grimsey O. D.)!. W. Iceland: Reykjavik!; Brjanslækiir 

 (H. J.)!. 



Both the piants agreed exactly with the specimens collected by 

 C.Jensen in the Færoes. A. littorale, which is a Sub-arctic-Arctic form, 

 is probably widely distributed. It has been found not only in the 

 Færoes and in Iceland but also on Jan Mayen (Dusén) and in Sweden, 

 on Gislo near Troså (Arnell). It has as yet been found sterile only. 



279. Amblystegium compactum (C. M.) Br. eur. 



Vestmannaey (H. J.;!). SW. Iceland: Ondverdarnes, in a well toge- 

 ther with Trentepohlia aiirea (H. J.)!. 



On Vestmannaey this species occurred rather frequently on the sides 

 of clefts and caves in tufF rocks. It grew there in company with 

 Trentepohlia, especially in piaces where water was percolating through. 

 and occurred sometimes in compact cushions several cm. deep, some- 

 times as a tliin covering. The Iceland specimens agree exacth' wilh 

 North American piants of A. compactum; occasionally, however, the 

 leaves especiall}' of the forms growing as thin coverings are somewhat 

 broader, with shorter cells. 



W. Monkemeyer and L. Loeske (Revision einiger Amblystegien 

 aus dem Herbare Limpricht; Ungarischen bot. Blåtter, 1911, p. 273 refer 

 Amblystegium salinum Bryhn to A. compactum as var. salimim (Bryhn 

 Mkm. On investigating numerous specimens of A. salimim I have, how- 

 ever, arrived at the conclusion tliat these two species are in no way 

 connected with each other. Amblystegium compactum forms compact, 

 dark-green tufts with a somewhat silkj' lustre, closely interwoven in the 

 interior with rust}- brown rhizomes which proceed partly from the stem 

 and partly, in very great numbers, from the under side of the stem- 

 leaves. The stem is prostrate with apex rising upward , and witli 

 numerous branches. The leaves are very close-sct, longh' decurrent. 

 erectly spreading and secund. The stem leaves taper from a broadly 

 ovate base to a long and slender point with strongly curved back apex. 

 The branch leaves are narrowly lanceolate. often with apex curved. 

 The leaf-margin is sharply toothed along its entire length. and especially 

 the lowermost teeth are often turned outwards or towards the base. 

 In the branch leaves the nerve reaches to the apex and is of almost 

 equal width along its entire length. straight. or sometimes slightly sinuous. 

 The leaf-cells are narrower than in any other Amblystegium, 0.005— 



