100 H. MØLHOLM HANSEN 
see, the following species were exclusively associated with this ve- 
getation: Taraxacum laevigatum, Epilobium anagallidifolium, Carex 
lagopina, Gnaphalium supinum, Pirola minor.” "Of the two dominant 
species, Salix herbacea and Sibbaldia procumbens, Salix herbacea is 
found in the greatest proportion. They either occur as separate 
dominants, or they dominate together intermixed with one another, 
and then either in equal number or with preponderance of the one 
or the other.” 
V. The Philonotis fontana Dy. “On damp gravel and at 
small springs small cushions of Philonotis fontana occur. In these 
light-green cushions of moss some flowering plant is generally met 
with, Cerastium trigynum and Saxifraga rivularis especially show a 
predilection for these spots. These moss cushions correspond to 
the dy occurring at lower levels.” 
The second type of vegetation which H. Jönsson distinguishes 
is that of rock pools. 1900, p.20 he writes: “Up the mountains, 
though not at very high levels, there occurs a characteristic vege- 
tation met with near pools, the vegetation of the rock pools; these 
pools are especially Eriophorum pools where E. angustifolium is 
solely predominant. They are extremely poor in species, yet we 
may mention the occurrence of scattered Carex rostrata, C. pulla, 
and C. alpina.” 
The third type of vegetation is the Grimmia heath. We have 
previously dealt with this vegetation (p. 40) with the main result 
that it belonged to the higher regions of the country to the south 
and east of the jokull line. It was most abundantly developed in 
the foggy and rainy regions of East Iceland, decreasing to the 
westward, and being absent in the north. “In the lowlands and at 
the lower levels of the mountains it changes in time and gives 
place to other plant societies; as a rule many phanerogams and 
vascular cryptogams are intermixed with it. These decrease con- 
siderably with increasing height above the sea, and have almost 
entirely disappeared from the Grimmia heath of the highest levels 
(at c. 600—700 m.); there only solitary, very widely scattered, com- 
mon fell-field plants are met with.” 
A comparison shows a great, but probably more apparent than 
real, difference between the vegetation schemata of the two authors. 
Stefansson describes the following types: melar, mo, myri, and 
snow-patch, Helgi Jönsson: fell-field (with sub-divisions gravelly 
flats, screes, the Anthelia crust, the Salix herbacea and Sibbaldia 
