THE BRYOPHYTA OF ICELAND 419 



qucnt. It occurs both in bogs and along the banks of streams, and 

 also on inundated gravelly ground, usualh' interniixed in tufts of mosses 

 such as Cinclidium. Miiiiun cinclidioides. Sphagnum and Hijpmim spp. ; 

 also on wet gravelly soil associated with Lophozia qninqiiedcnkda, Ce- 

 phalozia bicuspidala and othcr Hepaticæ. Only sterile specimens have 

 been found. 



Fam. TRIGOXANTHEÆ. 



58. Cephalozia bicuspidata (L.) Dum. 



Ver}' common on earlh. damp gravelly soil, hunius-covered rocks, 

 and in bogs up to a height of about 600 metres above sea-level, espe- 

 cially in NW., N. and in parts also of E. Iceland, while it appears to 

 be more rare in S. Iceland. It grows parlly in large cushions, for 

 instance on damp ground by streams, partly interniixed in tufts of 

 mosses especially Sphagnum and Dicrannm spp. and thrives best on a 

 somewhat damp substratum. Found as a rule in fruit. It varies con- 

 siderably as regards size and colour. 



Var. Lammevsiana (Hub. Breidler grows on very wet ground, for 

 instance along banks of streams, where it forms large green mats in 

 association with other Hepaticæ. It is especially common in XW. Ice- 

 land. The bog-forms, which grow erect among Sphagnum, are slender 

 with spreading leaves. On damp slopes a dark-brown-to-black form 

 frequently occurs, often forming very extensive carpets; it corresponds 

 most closely with var. Loeskeana Schiffner) K. M , in previous lists it 

 w^as referred to var. Lammersiana. At the head of deep lava-caves 

 and at the bottom of lava clefts it occurs in association with Alicularia 

 scalaris as much elongated shade-forms. 



Note. Cephalozia Francisci is recorded by Morch from Hafnar- 

 fjordur, but the specimen in the Botanical Museum is C. bicuspidata. 



59. Cephalozia ambigua C. Mass. 



NW. Iceland: Laugarland, fr. !. 



It grew there in small brownish tufts on the damp ground at the 

 bottom of the valley. 



60. Cephalozia pleniceps (Aust.) Lindb. 



Common in all parts of Iceland except in the southern part. where 

 it appears to be rare. It is especially common in XW. Iceland and 

 forms there one of the most frequently occurring Hepaticæ. 



It occurs especially on damp ground and in bogs, woven into tufts 

 of Sphagnum. Dicranum and Mnium hornum or associated with Lophozia 

 Kunzeana, L. quinquedenlata and other Hepaticæ and as a rule bears 

 calj'ces or fruit. It occurs most frequently up to a height of about 

 300 metres, but it is also often met with at far greater attitudes. 



Var. macrantha (Kaalaas et Xichols.) K. M. is widely distributed on 

 wet ground. and grows in association with similarly elongated forms of 



