20 MR. I. H. BURKILI ON 
Tar Frora or Vavav, one of the Tonga Islands. By I. H. 
Burkitt, M.A., F.LS.; with a short Account of its 
Vegetation by CuartEes STEELE CROSBY, M.A. 
[Read 20th December, 1900. ] 
Tux Tonga or Friendly Islands are composed of three groups: 
to the south is Tongatabu, a low coral island, with Eua near 
it; in the centre lie the Habai Islands, small and numerous; and 
to the north is Vavau, with its attendant islets. 
They are the summits which rise from an extensive submerged 
plateau—the higher ones a line of volcanoes. Eua attains to 
more than 1000 ft.; Vavau has two hills rising to 600 ft., and 
some of the volcanoes exceed Eua in height. 
“ Generally,” says Lister *, “all the high ground of the group 
is either the summits of volcanoes, active or extinct, or com- 
posed of reef-limestones,” and “while the contour of the sea- 
bottom, with the great southerly extension of the Tonga plateau, 
suggests that a closer connection may at one time have existed 
between New Zealand and land to the northward, the geological 
structure of the preseut Tonga Islauds would not lead us to 
expect that an ancient fauna and flora survives on them ; for all 
the high ground of the group either consists of the outpourings of 
volcanoes or has been submerged within the period during which 
the existing reef-limestones have been formed.” 
Tongatabu has been visited by more collectors of plants than 
all the other islands. Cook touched at it in each of his three 
voyages, and the specimens then obtained are in the Natural 
History Museum, 8. Kensington. It was visited by the United 
States exploring expedition under Captain Wilkes, by the 
‘Challenger,’ and by the German ‘ Gazelle’ expedition. Graette 
collected all bis Tonga plants in it, and J. J. Lister and Sir 
Everard Home many of theirs. 
Vavau was visited by the ‘ Gazelle’ expedition; but I only 
know of the collection there by the officers of this vessel of three 
marine plants. Barclay, Harvey, and Sir E. Home also collected 
in it. 
Of other islands in the group, Eua was explored by J. J. Lister, 
Lifuka by Harvey, and Nomuka by Forster. The last two are 
anong the Habai Islands. 
All the collections of the travellers named were made use of by 
Mr. W. B. Hemsley when he published through this Journal 
* J.J. Lister in Journ. Linn. Soc., Bot. xxx. (1894) pp. 160, 162. 
