1883. ] The Geology of Central Australia. I1i7 
gland. The cast-off cuticles are found toward the center of the 
knots formed by the mites while the adult individuals occupy the 
periphery, their heads being directed towards the bottom of the 
gland. He considers that the habits of the pig would render 
contagion easier than in other animals, and thinks that had the 
swine he examined not been killed, the result of the disease 
would probably have had as fatal an issue as is generally observed 
in the similar disease in dogs. 
:0:—— 
THE GEOLOGY OF CENTRAL AUSTRALIA. 
BY EDWARD B. SANGER. 
pe geology of the great central basin of Australia has until 
recently been a matter of some uncertainty. From analogi- 
cal reasons conclusions have been formed which are more or less 
correct. Still at best they were but shrewd guesses. Our know- 
ledge has been of a limited kind. The various explorers who 
have ventured to cross the continent have seldom taken any 
scientific men with them. Hence the reports received from time 
to time of this serra incognita have been vague and conflicting. 
Australia nevertheless has had not a few advantages in its scien- 
tific history. Many men of science whose reputation is now 
world wide, first became known to fame by their work on Austra- 
lian shores, But the attention of naturalists has been restricted, 
for the most part, to the east coast of the continent, while the 
remainder has been comparatively neglected. This, to a certain 
extent, was unfortunate, as the east coast possesses the novel Aus- 
tralian features in the least degree. It shares its peculiarities with 
other approximately well-known regions. Thus on the north-east 
Coast there is a large intermixture of Asiatic characters. These 
are less marked as the coast is followed to the southward, but 
still there is a large proportion of forms belonging to the Pacific 
islands, New Zealand, &c. On the south coast, however, the case 
1s different, Here the flora and fauna are peculiarly Australian. 
The Physical differences between Sydney harbor and Melbourne 
are slight, but according to Tenison-Woods, the marine fishes are 
of different species. The geological structure of the south and 
“ast coasts also differs widely. 
aken in its totality Australia is built on the true continental 
Model: It has the characteristic elevated borders and the de- 
