40 Transactions. 
that of Dr. Arber (1917) for New Zealand. To the former is due the Triassic 
and Jurassic maps here given (with minor modifications). Extensive 
fresh-water deposits formed in the neighbourhood of Sydney, comprising 
the extensive conglomerates, shales, and sandstones of the Narrabeen 
Hawkesbury series, of probably early and middle Triassic age. The basin 
of deposition probably discharged into a northward- extending gulf ancestral 
to the Tasman Sea. In Rhaetic times the area of sedimentation increase 
A second basin formed in south-eastern Queensland (the Ipswich series), 
and another, probably in Tasmania, discharging into the same gulf, which 
seemed to have reached a maximum extension at this time, for the 
deposition of the Rhaetic lacustrine Wianamatta shales above the Hawkes- 
y sandstone was interrupted near its close by a brief incursion of the. 
sea passing from this gulf as far westwards as the Blue Mountains. Here 
it deposited an argillaceous limestone containing a small group of ostracods 
and foraminifera, “a brackish or estuarine fauna having a curious inter- 
mingling of Rhaetic and Lower Jurassic types with others more propery. 
referable to the Upper Palaeozoic of Europe" (Chapman, 1909).* It is 
interesting to note the close approximation in time between this temporary 
ingression of the sea into eastern Australia and its regression from New 
Caledonia. 
Jurassic. 
The Jurassic period witnessed a wider extension of these lacustrine 
deposits. Walkom (1918) shows them as stretching from the Cape Yorke 
Peninsula southwards and to the northern parts of South Australia and 
of New South Wales. He is of the opinion that this basin discharged 
A second basin is that comprising the Jurassic coalfields of Victoria 
and eastern Tasmania, which Walkom thinks may have drained into the 
Southern Ocean. The intervening region of the present Tasman Sea, he 
considers, was probably for the most part a land area, the coast of which lay 
east of New Caledonia (which was land till near the close of Jurassic times), 
but west of New Zealand, which formed the littoral zone across which 
the strand fluctuated (until the early part of Cretaceous time), producing 
‘intercalated marine and fresh-water deposits, the latter predominating in 
the latter part of the period. The comparison of the work of Walkom on 
the Australian flora, and of Arber on that of New Zealand, briefly sum- 
marized by the writer (Benson, 1919), док a very general soia 
though with comparatively few forms common to the two regions 
general, also, the Australian Mesozoic flora ind four times as s 
species as t that of New Zealand, perhaps due to the unfavourable littoral 
habitat of the latter, and the modifications which have ensued during 
their migration back and forth with the fluctuation of the coast-line. The 
general conditions indicated continued until the commencement of the 
Cretaceous period, the highest plant-beds in this series in New Zealand 
being those "t Waikato Heads, which Arber considers of Neocomian age: 
in these, associated with С Cladophlebis and T'aeniopteris, appear angiospermous 
leaves (Artocarpidium), which seem to be more related to the figs than 
to any other modern plants. Of about the same age as these are the 
much larger floras зис by Walkom (1919) from the Burrum and 
* It is perhaps more dian x ойе. that the time-range of the “forsininitero 
eee нА be analogous with that suggested by the fish-fossils in the Wainamatta 
series (Woodward, 1908). 
