PAL.EONTOLOGICAL EVIDENCE OF THE ROSS REGION 315 



asymmetrical, from what dii-ection the thrust has proceeded. As far as can be 

 judged from Andersson's sketch section (op. cit., p. 25), the folding force at Hope 

 Bay has come from a general north-west direction. 



We can now jmss on to the Palseontological evidence of the Ross area. The 

 oldest rocks which have so far yielded fossils in that area are the ArchceocyathiruB 

 limestones of Cambrian age, found as fragments in an extensive limestone breccia at 

 the foot of the great granite monoliths of Lower Glacier Depot near the mouth of 

 the Beardmore Glacier. These limestones are considered by Mr. C. S. Wright of 

 the late Captain R. F. Scott's Expedition to be probably in situ near Mount Adams, 

 on the Beardmore Glacier, and in the opinion of Professor Skeats, also at Buckley 

 Island, on the same glacier. These have been described by Mr. T. Griffith Taylor 

 early in the Memoir. Taylor draws attention specially to the geographical position 

 of the Arch(tocyathin(e horizon, stating that hitherto the occurrence nearest the 

 Poles of these fossils had been that of Waigatch Island, to the north of Russia in 

 lat. 70° N. Adopting Professor Skeats' determinations of the limestone at Buckley 

 Island as containing Archceocyathince, they would have ranged in Cambrian time 

 in the Antarctic from at least 83^' to about 86° S. In this summary Taylor con- 

 cludes that of the five families of the Archceocythince alliance (vide p. 105 of his 

 Memoir), two are certainly represented in the Antarctic, viz. the Archceocyathince 

 and the Spirocyathidce. He considers that ArcJmocathus and Protopharcetra are 

 certainly represented, and show close affinities with" the South Australian forms. 



Associated with these fragments of the Archceocyathince is the abundant 

 dendritic organism which Mr. F. Chapman classes with the supposed calcareous 

 plant Solenopora* 



No fossils were obtained by the Shackleton Expedition on any higher horizon 

 until that of the Beacon Sandstone is reached. Here only one determinable fossil 

 was found, and even that in a somewhat imperfect state of preservation. As deter- 

 mined by Professor Goddard it pi'oves to be a true wood, showing medullary rays. 

 Professor Lawson of Sydney University is of opinion that the wood may possibly be 

 angiospermous, but this is doubtful. The formation having been extensively in- 

 truded by the diabase sills may be considered to be Pre-Upper-Cretaceous, if the 

 sills there, as in Tasmania, are Post-Jurassic to Upper Eocene. At present we 

 provisionally class the Beacon Sandstone as Gondwana. 



AVhile admitting that some of the sandstones below the coal-measures may be 

 older than Gondwana, and some of the highest sandstones possibly newer than 

 Gondwana, the fossil plants recently collected by the late Captain R. F. Scott and 

 Dr. E. A. Wilson, from the top of where Shackleton and Wild discovered the coal- 

 measures at the head of the Beardmore Glacier, and those obtained by one of us (R. E. 

 Priestley) from the Priestley Glacier, as well as the fossil fish plates found by 



* A very important and interesting paper on Solenopora and allied fossil algae, chiefly from the 

 Carboniferous, has recently been published by Professor Garwood, 



