PREFACE. 



beds ; to which not only great interest attaches as affecting the 

 geology of so large an area of the colony, but fi'om the fact that 

 the valuable leads of drift, or so-called alluvial, gold deposits, are 

 proved by the researches of the Geological Survey to have various 

 geological ages in the great Tertiary period — ages which can only 

 be determined satisfactorily by a study of the palseontology of such 

 of the beds as are fossiliferous. 



The first plate illustrates a most important specimen of that 

 singular animal, the Marsupial Lion of Owen ( Thylacoleo carnifex), 

 which enables us to make important corrections in the most recently 

 published views of the dentition of the anterior part of the skull, 

 in which some of the teeth here figured had not previously been 

 found in situ. 



The second and third plates are devoted to the illustration of 

 the most interesting of all Palaeozoic fossils — the Trilobites. Two 

 of the species of Phacops are absolutely identical wit\i forms 

 abounding in the UjDper Silurian rocks of Eurojie — one of them 

 British, and the other common in the Silurian basin of Bohemia. 

 A species of Homalonotus., figured on the thu-d plate, collected by 

 Mr. Harrison and presented by him to the public collection, is a 

 remarkable Australian addition to the range of this genus, and the 

 same may be said of the species of Forbesia and Ziichas, figured on 

 the second plate. 



The fourth plate is devoted to illustrations of a species o( Aiuria 

 scarcely distinguishable as an Australian variety from the Upper 

 Eocene and Lower Miocene Aturia zic-zac of Europe ; and as this 

 genus is not known in the recent state nor in the Newer Pliocene 

 Tertiaries, its presence has an important bearing on the determina- 

 tion of the age of our deposits in which it occurs. 



The fifth and sixth plates are devoted to some Gasteropoda of 

 certain Tertiary beds, probably of shallow-water origin, illustrating 

 two species of the genus Haliotis very unusual in Tertiary forma- 



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