October, 19 30 The Queensland Naturalist S3- 
in this later development, namely Etheridge’s own work 
on the Cretaceous faunas of Central Queensland, 
Walkom’s invaluable account on the Mesozoic Floras,. 
Longman’s descriptions of the vertebrate faunas, and 
Tillyard’s monograph on the Mesozic Insects. The last- 
named work is of particular interest, not only from its 
great biological value, but in that Tillyard made use of a 
new type of percentage classification to determine the 
geological horizon — a method recalling the classical 
revision by Charles Lyell of the Tertiaries. 
Within the past few years the science of Palaeon- 
tology has been undergoing a change that yet has hardly 
influenced the work on fossil faunas and floras of 
Australia. 
Always there have been two main attitudes towards 
Palaeontology — that of the field observer and that of the 
museum specialist. The one worker is interested in the 
general succession of floras and faunas, while the other 
is concerned with the inter-relationship of species and 
genera within some one biological group. With the 
growing recognition of features of homoeomorphy and r 
particularly of late, since the theory of Orthogenesis has 
made such rapid changes in the attitude of palaeontolo- 
gists, the two “ schools,” if so they might be called, have 
become more closely related. The field palaeontologist^ 
intimately concerend with zonal successions, is relying 
more on phylogenetic developments to define such zones,, 
while the specialist in turn relies unon accurate zonal 
collecting to make his phylogenetic classifications more- 
quantitative and exact. 
Modern palaeontology has changed very markedly 
in two directions : there has arisen a demand for the 
closest possible zonal classification of faunas and faunal 
stages, while, on the other hand, it has been necessary to 
revise old generic classifications defining genera within 
very much more narrow limits than previously. Such 
modern work independently was begun upon the 
ammonites by Hyatt and Buckman in the latter half of 
last century, Hyatt working on Museum material, and 
Buckman tracing out the progressive development of 
species through the sequence of beds exposed in the 
British sections. Since that time similar work has been 
carried out on other branches almost exclusively by field 
palaeontologists — Marr, Nicholson, and Miss Elies on the 
graptolite succession; Vaughan, Carruthers and Stanley 
Smith on the Carboniferous corals; Wedekind on the 
Silurian and Devonian corals; Walcott and Ulrich on the 
Lower Palaeozoic trilobites ; and so on. To some groups,. 
