-71 
Campanula ullginosa Rydb• f Phalarls arundi nacea L. , Clematis 
virgin!ana L., Leersla oryeoldes ( L•) Sw •, Kumulus Lnpulus 
I<« , Ranunculus Pennsylvania us L. f., Gal ium Clayton! Miohx., 
Radioula palustris (L.) Moench., Garex filiformis L., and 
Oarex tribuloides Wahl* 
The grassy marsh described above un¬ 
doubtedly oocupies the position of a former delta. It 
thus represents a stage in the gradual filling up of the 
valley with sediment and organic remains. 
STOIMAHI 
The ranges of the Porcupine Mountains are 
entirely surrounded by a low plain, so that the mountains 
were islands for some time after the final retreat of the 
ice sheet. As the water subsided, the higher ranges to 
the south were first uncovered. Pioneer invasion probably 
took place where the wash of the waves was not too severe, 
following stages analagous to those found in the present 
shore line. At the present time,these southern ranges or 
hills, including Government Peak, the highest point, are 
clothed with a mesophytio forest to the very top (fig. !)• 
This mesophytio forest was possibly preceded by a zero- 
phytic coniferous forest dominated by pine species, as 
