54 
GRAPTOLITES OF AUSTRALIA 
be expected, especially when dealing with the succession of 
purely shaly deposits, but as a rule even then the coming 
in of new forms in abundance should be taken as an index of 
the passage to a higher horizon. This fact is one ux-)on which 
great emjihasis should be laid ; it is ujion this, the coming in 
of new forms, usually indicative of a more advanced stage 
in evolution, that the basis of modern zonal stratigraphy is 
laid; the persistence of old forms tends to vary greatly in 
different localities. There does not appear to be any justifica- 
tion for action which results from focusing too much 
attention upon the index fossil rather than upon the assem- 
blage, winch is the determining factor’.” 
A short history of grajitolite research was published and a 
correlation of the Victorian zones with those in the Northern 
Hemisx)here. 
They described and figured Diplogmptus (Glyptograptus) 
mistrodenlatus s}i. nov., Phyllograptus nobilis sp. nov., JDidy- 
mograptiis forcipiformis, 1). dependidus sp. nov., BracJiio- 
graptus etaformis gen. et sji. nov., and Goniograptus 
pcdmatiis sp. nov. 
E. A. Rijn^er (122) indicated the distribution of the zones 
of the Castlemaine and Darriwil Series at Ingliston, near 
Bacchus Marsh. She found in the Darriwil Series Zone D2 
characterized by the zone fossil Diplog raptus emstrodentatus, 
Glossograptus sji. and absence of Cardiogmptus morsus; D3, 
characterized by C. morsus and the absence of Oncograptus ; 
D4, with Cardiog raptus morsus and Oncograptus sp. ; D5-4, 
with Oncograptus biangidatus and 0. upsilon and D5 with 
0. upsilon and the absence of Cardiograptus. In the Castle- 
maine Series she found Zone Cl with Bidymograptus 
caduceus (maximum develojiment) and Oncograptus absent. 
She x^ublished detailed majis and sections. 
D. E. Thomas (123) gave lists of grajitolitcs from Lower 
and Ux)X)er Ordovician localities in the area to the north and 
north-west of Riddell and including x)arts of the Parishes of 
Kerric, Monegeeta and Rochford. The localities are indicated 
by symbols on the maj) juiblished with the pajoer. He records 
for the first time in Australia Biplograptus (Amplexo- 
graptus) cf. arctus,B. cf. pageanus, Climacograptus minimus, 
C. puiillus cf. mut. eximius and Bicellograptus forchammeri 
var. flexuosus. 
1933. — D. E. Thomas and R. A. Keble (126) imblished 
a comprehensive x^Rpei’ on the Bulla- Sunbury area and 
discussed the Silurian sequence in the Melbourne area. They 
outlined the history of ideas concerning the Silurian and 
