18 Transactions. 
probably connected with that in the South Australian trough. The possi- 
bility that this sea extended south-westwards to the Macdonnell Ranges 
was suggested by Howchin (1914) on account of the occurrence therein of 
Cryptozoón in dolomitic limestones which according to Chewings lie uncon- 
formably beneath fossiliferous Ordovician rocks. 
In regard to the origin of this fauna the evidence is as yet rather 
fragmentary; indeed, Reed (1910) and Haug (1911) considered that no 
palaeogeographical conclusions of much value could be based on it. Since 
they wrote, however, Walcott (1913, 1916) has examined representative 
Australian forms, and made valuable comments on the bearing thereon of 
the Cambrian faunas of Asia. “ The Lower Cambrian Man-t’o Redlichia 
fauna . . . is far as known, very distinctive, and confined to the 
Asiatie continent and Australia. Its transgression over eastern and south- 
eastern Asia was somewhat later than the transgression in the Siberian 
area now occupied by the Lena and Yenesei Rivers. . . . The dis- 
tribution of the Redlichia of the R. noetlingi form serves to demonstrate 
that the transgressing Lower Cambrian sea that contained Redlichia was 
confined to eastern and south-eastern China and northern India. The 
presence of Redlichia-like trilobites in southern and western Australia 
indicates that there was a direct connection between the Punjab Lower 
America.” In another sentence, however, he states, “ The Siberian 
fauna is, however, that of the Lower Cambrian of Australia, Sardinia, and 
North America " (in which Archaeocyathinae are present). According to 
H. Mansuy's (1912) work, the Lower Cambrian Redlichia fauna is present 
à : 
it was a centre of evolution and dispersion for these forms, but this is not 
certain. 
It was perhaps during the middle part of the Cambrian period (Tilley, 
1919) that there occurred these extensive crust-movements a i 
Mount Lofty Ranges, and possibly have affected the region stretchin 
north-eastward to the western side of the Broken Hill area though the 
e Upper Cambrian (Heathcoti TOT WE 
Spread, and were laid xs in 86 tater’ of Victoria аге more wide 
Limestone is rarely t 
an forms Lingulella, Acrothele, Billingsella, 
with those of a more Ordovician aspect 
