1917] MacCAUGHEY—HAWAIIAN FLORA 93 
years have failed to disclose new habitats or localities for many of 
these precinctive plants. For example, Drosera longifolia occurs 
only in the summit bogs of Kauai; Pelea pallida is limited to Kaala, 
in the Waianae Range; many of the lobelias, cyrtandras, and 
kaduas are sharply precinctive; Lagenophora mauiensis occurs 
only in the Eeka swamps; and 4o or 50 other well defined illus- 
trations might be cited.’ 
The limitations of this paper forbid any extensive discussion 
of the remarkable geological history of the Hawaiian Archipelago, 
and the bearing of this history upon the development of the land 
floras It is sufficient to state that the older islands lie to the 
westward, and that the eastern end of the chain comprises the 
youngest elements of the group. Many years ago HILLEBRAND 
noted the contrast between the vegetation of Kauai and Mauna 
Loa as two extremes. He stated that ‘the Kauai. species ms the 
leading Hawaiian genera are in all instances the most specialize 
to be distinguished by more striking characters than the ae 
Examples are Schiedea, Raillardia, Dubautia, Campylotheca, Lipo- 
chaeta, Pittosporum, and Pelea. The proportion of species peculiar 
to Kauai with spd giana welled cag uecen 
67: a Or 17.5:100.” 
The studies and explorations oe ‘succeeding botanists lave ae 
tended to confirm and intensify this contrast. Kauai, Waianae = 
on Oahu, the east end of Molokai, West. Maui, Kohala and Cg 
Waa-waa on: Hawaii, these are regions much more ancient — a 
the land areas with which they are immediately connected, < 
their vegetation gives abundant evidence of their antiquity. : Coy : 
nmer of t916 Professor ie A peceipaan of mee oe es 
