574 



A. HESSELBO 



ferum, Hypnum imponens, Mnhim hornum, M. undulatum, M.serra- 

 tum, Fissidens osmundoides and Enthostodon ericetorum. On a stone 

 partly inundated by the hot water, which had a temperature of 

 about 50. Fissidens osmundoides, Blindia acnta, Dicranella squar- 

 rosa, Enthostodon ericetorum, Anthoceros punctatus, Aneura multiftda 

 and Scapania irrigua grew intermixed. 



Fig. 23. Deildatunguhver. To the left is the slope with the hot springs. The part 

 in the middle is saturated with the hot water and covered with Sphagnum papillo- 



sum, Polytrichum commune and Hydrocotyle. 



Deildatunguhver (Gronlund's Tunguhver) (Fig. 23) is 

 situated north of the river and opposite to Kleppjarnsreykir. It is 

 mentioned by Gronlund (1877, p. 349), who states that the surface 

 temperature of the ground at the top of the hill was 23 R, and 

 that there Polytrichum commune, Sphagnum cymbi folium, S. cuspida- 

 tum and a Campy lopus (C. flexuosus) not determined with cer- 

 tainty grew in the warm ground. Deildatunguhver is one of 

 the hot springs of Iceland which discharge the greatest amount 

 of water, and consists of a row of holes at the foot of a hill 

 6 8 metres high, whence an enormous quantity of water and 

 steam is ejected with a great noise. The masses of steam, 

 which can be seen for miles, enshroud the surroundings of the 

 spring with so dense a cloud that it is hardly possible to ap- 

 proach without getting soaked through. Below the hill the water 



