406 A. HESSELBO 



older lists, and Gronlunds records it from nianj' localities in Iceland, 

 but all the specimcns found in thc collections under this name are 

 Ihose of Pellia Neesiana. 



15. Blasia pusilla L. 



N. Iceland; Reykum (Grl.)!; Melar (Grl.)!; several piaces near Modru- 

 vellir near Eyjafjordur O. D.)!; Reykjalaug in Fnjoskadalur (O. D.)!; 

 Oxnadalur!; Stadr near Hrutafjordur!. W. Iceland: Gilsbakki!; common 

 in Reykholtdalur!. S. Iceland: Reykirdalur!. 



Only the (^ plant has been found in Iceland. 



This species occurs in rock-clefts and along Ihe banks of slreams, 

 on wet gravelly ground, and also on cla\' near hot springs. P'or instance, 

 it grows abundantly in Reykholtdalur, and more scantily in Rej'kir- 

 dalur on the damp, steaming clayey flåts, the temperature of vvhich 

 just below the surface is about 25''— 40^; it is found associated with 

 Gymnocolca inflata, Haplozia crcniilata and Fossomhronia Diimoiiieri. 



On banks of streams it usualh' grows rather scantily and associated 

 with Dicvanella crispa, Pellia Neesiana, Didijmodon nibelliis, Aiigstiomia 

 longipes, Scapania subalpina, ctc. 



Note. Morchia Blyttii (Morch) Rrockm. is recorded by Gronlund 

 to occur in Rrynjudalur, but the specimens preserved in the Botanical 

 Museum in Copenhagen belong to Blasia pusilla. 



Fam. CODONIEÆ. 

 16. Fossombronia Dumortieri (Hub. et Genth) Lindb. 



N. Iceland: near Mvvatnl. S. Iceland: near hot springs on Rey- 

 kjanes (Ostf. !); Reykir!; Thorhikshver!; Laugaråshver!; Sydri Reykjahver!; 

 Thingvellir!; Kolvidarholl; Geysir (Ho.;!). W. Iceland: common near 

 hot springs in Reykholtdalur!. 



Fossombronia Dnnwitieri is onc of those species which are rarel}*^ 

 absent from the neighbourhood of any hot springs if only the water 

 does not contain too much sulphurelted hydrogen. There it grows on 

 warm clayey flåts with a temperature of about 40^, and cspecially on 

 damp slopes along the outlets of springs; as a rule it sets fruit which 

 ripens during June— July. 



In Reykholtdalur it is common near all the hot springs, also near 

 the springs on Riskupstungur, near Geysir and on Rcykjanes. In Reykir- 

 dalur, where thc majority of the springs give out abundance of sul- 

 phuretled hydrogen in their vapours it occurred less frequently, but 

 nevertheless was found near several springs, also around some small 

 fumaroles near Kolvidarhol from which issued aqucous vapours im- 

 pregnatcd with sulphurettcd hydrogen. It grows in all these localities 

 associated with olher Hepaticæ, for instance Gymnocolca inflata, Haplozia 

 crennlata and Anlhoceros piinctalus. Near Myvatn it was growing around 

 a fumarole, on a damp clayey flat with a temperature of about 40°, 

 associated with Riccia bifarca and Haplozia crcnulala. The only place 



