THE AUSTRALIAN NATURALIST. 145 
warmer parts of the eartli. This wide distribution implies 
that they are an old family, and this is borne out by many 
archaic structures, such as amphicoelous vertebrae, which they 
present. They are indeed the oldest family. of modern 
Lacertilia. Many points in the distribution of lizards support the 
idea that these so-called old families of lizards are indeed quite 
recent compared to many other groups of animals. The lizard 
fauna of Madagascar, for instance, is intimately related to that 
of Africa, and its lizards belong only to old families. Now, 
since Madagascar separated from the mainland not earlier than 
mid-tertiary times, it may be inferred that the newer families 
of lizards are of quite recent origin, and the old families com- 
paratively recent. 
Asregards means of dispersal it is interesting to note that 
geckos are quite non-aquatic; no gecko will willingly enter 
water. But they can cling firmly to logs and timber, and can 
live without food and water for months, so that they are very 
well adapted for transportation from place to place on floating 
tree-trunks, ete. 5 
It is a very striking fact that most families of vertebrates 
that have a wide distribution and do not cross Wallace’s line 
(a line running between Bali and Lombok, then through the 
Straits of Macassar, east of Borneo, and on to the east of the 
Philippines), are absent from Madagascar. This is well 
illustrated by the Lacertidae and other families of lizards. 
The Iguanidae, almost wholly American, with two genera in 
Madagascar, present a very peculiar distribution which, per- 
haps, can only be explained by the suggestion that it is not a 
natural family, but that the American and Madagascar branches 
present a case of convergent evolution, the two groups having 
been developed independently. It is very doubtful, too, 
whether some of the other large families like*the Scincidae, 
with a very wide distribution, should be regarded as natural 
families. 
The Chameleons have a distribution remarkably parallel 
with that of the Lemurs. The majority of the species are 
found in Madagascar, but a few are found also in Africa, 
Southern Asia, and the Hast Indies. 
NOTES ON THE GENUS PSEUDOPHRYNE. 
(By H. Clunies Ross). 
Mr. Boulenger, compiler of the British Museum Catalogue 
of the “ Bactrachia Salientia,” in a footnote to his descriptions 
of the species Pseudophryne australis and P, bibronii, expresses 
his uncertainty as to whether these two do constitute, different 
species or are merely varieties of the one. It is not, for one 
