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XXVII. — Scottish National Antarctic Expedition, 1902-1904: Cambrian Organic 
Remains from a Dredging in the Weddell Sea. By W. T. Gordon, D.Sc., 
Reader in Geology, University of London, King’s College. (With Seven 
Plates.) 
(Read March 13, 1915. MS. received December 4, 1919. Issued separately June 9, 1920.) 
Introduction. 
From a biological point of view considerable interest must always attend any 
investigation of the earliest known organisms, and, although we may legitimately 
infer that a flora and fauna existed prior to Cambrian times, the organisms preserved 
for us in rocks of that age constitute, at present, the first chapter of palaeontological 
history. For this reason alone the Archseocyathinse are important, since they form 
part of the Lower Cambrian fauna. When, however, we consider that the genera 
included in the group are very distinct from one another (indicating that the family 
was probably of considerable antiquity even in those early times), that the types 
have, as far as we know, a wide geographical distribution, and that to certain skeletal 
characters usually associated with the Porifera they unite others more common 
among the Coelenterata, interest is still further stimulated. On the other hand, 
although recorded in great abundance from several widely separated localities, they 
are not, as a rule, common fossils in Cambrian strata, and consequently the group 
has not received much attention. 
The investigation of such specimens as have been obtained has been carried on 
along very different lines by the several authors who have studied them, and conse- 
quently it is often a matter of no little difficulty to correlate specific diagnoses. 
Thus Bornemann # based his specific determinations, to a large extent, on external 
shape, and to that end employed thin sections of the specimens, not necessarily 
cut in any particular direction through the organism. Taylor t employed several 
features in his diagnoses, chief among which is the diameter of the pores which form 
such a marked feature in all the skeletal elements. It is only fair to state that 
Bornemann also refers on occasion to the pores, but in this respect the plates 
which illustrate the memoir are more useful than the text. By a careful measure- 
ment of his photographs, a fairly accurate idea of the porous structure may often be 
obtained, even although it is not specially mentioned in the text. 
The method of investigation has depended greatly on the mode and state of 
preservation. Where the specimens are weathered out from the matrix, direct 
* Bornemann, “ Verstein. Sardinien,” Nova Acta der Ksl. Leop. -Carol. Deut. Akad. der Nat., vol. li and vol. lvi, 
Halle, 1886, 1891. 
t Taylor, “ Archaeocyathinse from Cambrian of South Australia,” Mem. Roy. Hoc. S. Australia, vol. ii, pt. ii, 1910. 
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