XXIV. 
CuARi.Ks Austin Gardner. 
1 find that South America contains many more* peculiar families than Australia, 
and South Africa about as many.” Tlie definition given by Diels for the Aus- 
tralian Element has already been quoted (p. 3), and 1 ha\'e already indicated 
that some of the groups included under his definition do not belong to this 
element. 
On the other hancl, there are certain families and groups tliat are either 
entirely Australian, or almost entirely so, vitli every genus represented in Aus- 
tralia, and but few external species. Apart from the strictly endemic groups 
it is difficult to deline with exactitude the Australian Element, or to di\*orce 
it entirely from the Antarctic, or the Palaeotropic Element. To illustrate this 
difficulty we may take the sub-family Leptospermoideae of the ^Myrtaceae. 
MYKTACEAE UEPTOSPERMOmEAE. 
Osho^'nia"^ 
Back'housia* 
Metrosideros* 
Bpe?'7nolepis* 
Lysicarpvs* 
Cloezia* 
Tepualia* 
jSyncarpia* 
Xanthoste^non 
Fleur ocaly pin 
Tristania 
Angophoi'a'^ 
Eucalyptus 
Leptospennum 
Agonis 
Kurizea 
Callistemon 
M elaleuca 
Lamai'chea 
Coiiothatmms 
Eremaea 
Ph ym at 0C07 pus 
Regelia 
Beaufortia 
Balaustio7i 
Baeckca 
A startea 
Hypocahjmma 
(a) Leptospermeae. 
(1) N. Australia 
(5) N. Australia 
(20) S. Africa, Indo-Malaya, New Zealand, Aus- 
tralia, Sunda Is. 
(2) New Caledonia 
(1) N. Australia 
(6) New Caledonia 
(1) Chile 
(2) E. Australia 
(18) trop. Austr., N. Caled. .... .. . 1 
(1) New Caledonia 
(22) Malaya, N. & E. 
Australia, N. Caled .... .... 3 
(5) E. Australia 
(500) Australia, Malaya, Celebes, Philip- 
pines .... .... .... .... 150 
(25) Australia, Malaya, N. Zeal. .... 10 
(13) S.W. Australia .... .... .... 13 
(18) temp. Australia .... .... .... 12 
(12) temp. Australia ... .... .... 2 
(120) Australia — one sp. extending to N. 
Caled., Malaya, and India .... 100 
(1) S.W. Australia .... .... I 
(3) S.W. Australia .... .... .... 3 
(7) S.W. Australia .... .... .... 7 
(2) S.W. Australia .... .... .... 2 
(3) S.W. Australia .... .... .... 3 
(15) S.W. Australia .... .... .... 15 
(2) S.W. Australia .... .... .... 2 
(00) Australia, Malaya, China .... .... 48 
(5) Australia .... .... .... .... 5 
(18) S.W. Australia .... .... .... 18 
