710 
DR W. T. GORDON ON CAMBRIAN ORGANIC REMAINS 
The following genera are represented : — 
Archseocyathus. 
Thalamocyathus. 
Archseofungia. 
Archaeosycon. 
Coscinocyathus. 
Coscinoptycha. 
Dictyocyathus. 
Dokidocyathus. 
Ethmophyllum. 
Metaldetes. 
Protopharetra 
Pycnoidocyathus 
Spirocyathus. 
Somphocy a thus . 
Syringocnema. 
It will be noted that all the genera from the Weddell Sea material are repre- 
sented in South Australia, and that two of these ( Metaldetes and Syringocnema) 
have not been obtained elsewhere. 
While the majority of the species in the two areas are distinct, yet some forms 
are common to both faunas, and one of the species, viz. Thalamocyathus trachealis 
(Taylor, sp.), is confined to these two localities. Even among the forms which are 
not specifically identical there are sometimes similar characteristics. For example, 
the species of Coscinocyathus from South Australia have, in the majority of cases, 
the pores on the inner wall equal in size to those on the outer wall, i.e. they are of 
the “ equivallum ” type. In other records the Coscinocyathidse have larger pores 
on the inner wall. The Antarctic examples described above approximate to the 
Australian “ equivallum” type. 
All these cases point to a close relationship between the Antarctic and Australian 
faunas of Lower Cambrian age ; and comparison with the Archseocyathus fauna in 
Sardinia, Canada, or Siberia shows that the forms are not nearly so closely allied. 
There is, however, one marked point of contrast, namely, the size and general con- 
dition of the specimens. Taylor has recorded specimens from Australia reaching a 
length of 6 inches and a diameter of 4 inches. The longest example from the Weddell 
Sea is little more than 1 inch, and the greatest diameter recorded is about §- inch. 
Again, as shown above, the walls and septa are in most cases thickened, while the 
interior of the cup is filled with adventitious structures. These features are con- 
sidered gerontic. The small size and apparently senile characters mark the Weddell 
Sea types and probably indicate life under adverse circumstances. It is interesting 
to note that the only complete specimens recorded from the Beardmore Glacier 
moraines were embryonic forms, according to Taylor. This is explained in the 
Report of the British Antarctic Expedition as due to the small size of the frag- 
ments of the breccia ; but none of the fragments of larger cups — as far as one can 
judge — indicate very large individuals. The small size may again be explained by 
adverse conditions of growth, and in that case can be correlated with the Weddell 
Sea forms. 
Taking all these facts into consideration, we seem driven to the conclusion that 
the life-types of Cambrian times in South Polar and Australian areas were similar, 
but that conditions towards the pole were less favourable for the growth of these 
