I -INTRODUCTION. 
The material desori'ocd in the following pages is contained in the collections 
of the INIining and Geological Mnsenni, Sydney ; the IMacleay i\rnscnm at 
the UnivxM’sity of Sydney ; and iii that of IMr. F. G. de V. Gipps, to whom I 
am indebted for the opportunity of examining a number of opalised shells 
from the Upper Cretaceous of White Clitfs.^ 
The iirst-mentioned series of specimens Avas collected at various times 
by the late Mr, C. S. Wilkinson, Government Geologist, his successor Mr. 
E, E. Eittman, Mr. H. Y. L. BroAvn, the present Government Geologist of 
South Australia, and at that time an officer of the Geological Survey of 
jV. S. Wales, and Mr. Charles Cullen, collector to the latter body, Avitli, in 
addition, donations to the Museum by private individuals. 
The specimens contained in the Macleay Museum were mostly 
collected by Mr, II. Gilliatt, late Inspector of Public Tanks and Wells, and 
Avere described by the late Pev. J. E. Tenison Woods. Eor the loan of these 
fossils I am indebted to the Committee of Management (Profs. T. lY. E. David 
and AY. A, lias well). 
The labours of Dr. P. L. Jack and bis Colleagues on tlie Geological 
O C5 
Survey of Queensland liave prOA'ed that the Cretaceous of that State is 
divisible into an Upper and a Lower Series — the “ Desert Sandstone Series ” 
of Daintree, and the “ Polling Doavus Eormation ” of Jack, the one resting 
uuconformably on the other. The Avovk of the Geological SurAxyors of 
N. S. AYalos has shoAvn that the same relations exist in this State, Avhilst 
surveys of Mr. II. Y. L. Brown, and the Pahnontological researches of the 
late Prof. P. Tate demonstrate a like superposition in South Australia. 
The life of the tAvo main divisions of the Queensland Cretaceous avc 
noAV knoAV to be practically the same, notAvithstanding the unconformability — 
at any rate so far as the organic remains from the fcAv fossiliferous localities 
in the Desert Sandstone Series permit us to arrive at a conclusion. These 
horizons arc — Maryborougli, on the east coast ; Battle Camp, near CooktoAvn ; 
and Croydon, in the Gulf country. 
A few additiDnal opaliseil forms were contributed l>y Air. H. A'. L. Urowii. 
A 
