72 
GRAPTOLITES OF AUSTRALIA 
Zone of Dicranograptus Mans 
Zone of Climacograptiis zvilsoni (according to Elies 
(119), 1932, this is C. baragzjuanathi, T. S. Hall) 
Zone of Climacograpius peHifer 
Zone of N cmagraptus gracilis 
Work by D. E. Thomas in the Romsey area on the zoning 
of the Upper Ordovician corroborates this classification to a 
certain extent; but faulting in the sections, their limited 
extent, the absence of certain zones, and the difficulty of 
obtaining well preserved specimens make a comprehensive 
account of the zones rather difficult. The remarkable 
similarity of the zones in the Upper Ordovician of Australia 
to those of Great Britain is striking, and with further work 
it may even be possible to adopt the English classification. 
The zone of ThceJlograptus cf. companatus appears to include 
the fauna of the zone of DiceUograptus anceps of the Euro- 
pean classification. Elies’ ])oints out that the “zone of 
DiceUograptns companatuH is conditional,” and that “in 
Scandinavia a small form of D. anceps occurs with this fauna; 
so that in all ]U‘obabi]ity it lies below the zone of I), anceps.’^ 
Harris and Thomas consider that until further detailed work 
is done, Thomas’s subdivision of 1935 (135) should be 
adoihod. 
The characteristic assemblages are as follows: 
Gisbornian. 
The zone of Nemagraptus is easily identified by the 
incoming of Nemagraptus, Dicellograptus sextans, B. divari- 
catus, Bic ran og ra ptus nieJiolsoni, B. zic-zac, CUmacog raptus 
hicornis, If all ng raptus mncronatus, and the various Lepto- 
rp'apH. The association is very similar in the next zone, but 
in it CUmacog rapt us peHifer and Mesograptus multidens are 
very characteristic. 
Eastonian. 
The base of the Eastonian is characterized by abundant 
Orthograpti. In the zone of Bicranograptus Mans, the 
zone fossil is abundant and CUmacog raptus tuhuUferus is 
characteristic. Bicranograptus cUngani occurs, but not in 
abundance. According to Elies, Climacograptus haragwanatM 
is synonymous with C. wilsoni. 
Bolindian. 
Pleurograptus is a rare form. Orthograptus quadrimucro- 
natus, however, is very characteristic. The beds containing 
1. Elies, G. L., Geol. Mag., Ixxiv, 1937, p. 487. 
Eastonian 
f- Gisbornian 
