1917] MACCAUGHEY—HAWAIIAN FLORA’ 95 
extinction, are Neowawraea phyllanthoides, Alectryon macrococcus, 
Alphitonia excelsa, Hibiscadelphus Giffordianus, H. Wilderianus, 
H. hualaliensis, Kokia Rockit, K. drynarioides, Clermontia halea- 
kalensis, Cyanea arborea, C. comata, and Hesperomannia arborescens. 
It may be estimated conservatively that probably several 
hundred species of angiosperms have become extinct since the first 
landing of live stock on these islands. PrRxKins has estimated 
that 300 species of native insects have been exterminated. The 
extinction of many of the highly specialized avian species is a 
lamentable and widely known fact. On the island of Oahu, for 
example, there are more extinct species of endemic birds than 
existing species. Numerous forms of the arboreal snails are now 
excessively rare. 
Ocean currents 
Hawaii is so remote from other land areas, and is so situated 
with reference to the great trans-Pacific ocean currents, that 
comparatively few plants have been added to her flora through 
the agency of water borne seeds. The shores and beaches present 
a striking contrast to the forested littoral of many South Pacific 
Islands, which have been well stocked with plants by the currents.” me 
_ Logs of coniferous species are thrown upon Hawaii’s windward 
shores after a long drift from the northwest coast of Amseica: eo ; 
These have probably brought seeds and spores in -_ crevices, : 
although there is no conclusive evidence on this 2 Bryan’s 
hypothesis is very suggestive in this connection. | =f is possible’ 
that in bygone ages, long ago, the movements of the Pacific may 
have been reversed, so that various plants from the Australian, — 
Polynesian, fast oe American regions that are well known here, : a 
= have | . carried to ae ae S ee i in one be soe : 
= Sie of the species that very pro tk = ba = Z a ” ‘intro . 
2 & Ocean currents are e Scacvola Lobelia, Heli ecb 
