676 The American Naturalist. [July, 
tribution of the parrots and the cystignathous frogs appears also to 
sustain the theory. The extinct alligator, Palimnarchus, found in 
Queensland and New South Wales associated with Diprotodon, 
strengthens the chain of evidence, as does the occurrence in Tasmania 
and Australia of Gundlachia, otherwise an exclusively American 
mollusc. 
As the name implies, the Autochthonian is the oldest member of the 
Australian faunas and floras. The date ofits arrival in Australia and 
the route which it traversed are lost in antiquity. Seeing that many 
resemblances exist between our vegetation and those of Timor and the 
southeast Austro-Malayan islands, perhaps these lands afforded the 
passage to Australia. 
Summary.—Superimposed, one above another, may be distinguished 
three divisions of Australian life. The earliest is the Autochthonian. 
Possibly this arrived from the Austro-Malayan islands, in or before 
the Cretaceous era, and spread over the whole of Australia. The next 
is the Euronotian. Probably this reached Tasmania from South 
America, not later than the Miocene epoch; many of the original in- 
habitants, particularly on the east coast, probably disappeared before 
the invaders. Thirdly, a contingent of Papuan forms seized on the 
Queensland coast, late in the Tertiary, and likewise largely extermi- 
nated their predecessors. 
Notes on a Snapping Turtle’s Nest.—On June 16, 1894, I 
saw a snapping turtle, Chelydra serpentina, in the course of two hours, 
dig a hole and in it lay twenty-two eggs. 
The hole was dug in gravel and was small at the top, but when an 
inch below the surface of the ground, it widened, and when finished 
was three inches in diameter and about four inches deep. The digging 
was done entirely by the hind feet used alternately. 
The eggs were crowded in place by the hind feet, as fast as they 
were laid. Then the hole was filled even with the rest of the ground. 
The nearest water was a small stream about thirty feet distant.—A. 
On some new North American Snakes, NATRIX COMPRESSI- 
CAUDA TENIATA subsp. nov.—Scales in twenty-one rows; four series of 
longitudinal spots above, those of the median pair forming two lon- 
gitudinal stripes on the greater part of the length ; the laterals forming 
stripes on the neck only. 
Labials ys, oculars 1-3; temporals 1-3. Frontal narrow, not 
widened anteriorly ; parietals rather wide. First row of scales keeled. 
