116 PROCEEDINGS OF THE ROYAL SOCIETY OF QUEENSLAND. 
This Zone has been divided into three Snbzones, on the presence or 
absence of the other ostracod species. In the uppermost of these Subzones, 
which is approximately 20 feet in thickness, Cypris munduranensis, 
Ilyodromus ? concentricus, Cypridopsis linearis , and Erpetocypris? 
subtriangularis are present, while Cyprinotus punctatus and Erpetocypris 
aequalis are absent. This subzone has been called Subzone A. Underlying 
it is Subzone B, approximately 50 feet in thickness, and characterised 
by the presence of Cypris munduranensis, Ilyodromus? concent ricus, 
Cyprinotus punctatus , and Cypridopsis linearis , and the absence of 
Erpetocypris aequalis and Erpetocypris ? subtriangularis. This in turn 
is underlain by Subzone C, which is approximately 45 feet in thickness, 
and is characterised by the presence of Cypris munduranensis, 
Ilyodromus? concentricus , Cyprinotus punctatus, and Erpetocypris 
aequalis, and the absence of Cypridopsis linearis and Erpetocypris? 
sub triangularis. 
The Zone of Ilyodromus? concentricus is overlain by Zone I, from 
which Ilyodromus? concentricus, Cyprinotus punctatus, and Erpetocypris 
aequalis are absent, but in which Cypris munduranensis, Erpetocypris? 
subtriangularis, and Cypridopsis linearis are present. This zone is 
represented only in the samples submitted from Bores III, VI, XII, and 
XIV, and, because of the long ranges of the species present, it is not 
possible to divide it into subzones. It is at least 25 feet in thickness. 
The Zone of Ilyodromus? concentricus — or Zone II — is underlain by 
Zone III, in which Ilyodromus? concentricus is again absent. In this 
zone, which is at least 100 feet thick, Cypris munduranensis, Cyprinotus 
punctatus, and Erpetocypris aequalis are present, but Erpetocypris? 
subtriangularis, Cypridopsis linearis and Ilyodromus? concentricus are 
absent. Unfortunately, owing to the long ranges of the three species 
present, it has not been possible to divide this broad zone into subzones. 
From this division into zones, based on a study of the eight species 
occurrence charts, an approximate correlation of the strata in the 
portions of the various bores examined has been arrived at and the 
accompanying chart drawn up. For security reasons, no information 
concerning the exact location, relative position, and depth of these bores 
is at present available. Accordingly, the accompanying chart does not 
suggest any structural phenomena, but is one of zonation and correlation 
only. Although the relative position of the various bores has not 
officially been disclosed, however, they are known to be quite widely 
separated from one another, so that little, if any, structure could be 
deduced with safety from a correlation chart, even if the exact spacing 
were known. 
The surface elevation, respectively, at Bores I, III, IV, V, VI, XII, 
XIII, and XIV has officially been given as 45, 80, 25, 20, 5, 25, 12, and 
25 feet, and this variation is shown on the correlation chart (Text Fig. 1). 
Discussion. 
In conclusion, it may be said that, although the ostracod species 
found in The Narrows Tertiary shales have proved somewhat disappoint- 
ing for purposes of close zonation, the recognition of various characteristic 
faunal assemblages has enabled the division into zones and approximate 
correlation of the strata in the various bores. 
