STUDIES ON THE VEGETATION OF ICELAND 121 
III. The knolly mo. The snow-covering and moisture of the 
soil are still greater. No solifluction, but incipient formation 
of knolls. 
IV. Jadar, peculiar to moderately moist soil with normal snow- 
covering and maximum formation of knolls. 
V. Myri. The soil is constantly moist, the ground-water coming 
up above the surface. Two formations may be distinguished, an 
upper, more dry, formation in which knolls occur, and a lower, 
more moist, formation in which the surface is level and without 
knolls. 
VI. Flöi. Constantly covered with water, the bottom level, no 
knoll formation. 
VII. Geiri. Snow-covering deep, bottom comparatively moist, 
especially in the lower formations, surface level, no knolls. 
The types of vegetation in other parts of the highlands seem 
to correspond to these. 
