﻿Vol. 66.] THE CAMBRIAN ROCKS OF COMLET. 51 



Discussion. 



The President (Prof. W. J. Sollas) welcomed this important 

 contribution to our knowledge of the Lower Cambrian faunas ; it 

 was no small triumph to have established a standard succession 

 by work in so restricted an area as Comley Quarry. The material 

 was fragmentary, and to have elicited so much sound information 

 from it reflected the greatest credit on the Author's skill and insight. 

 The determination of the true horizon of the Protolenus Fauna was 

 in itself a noteworthy achievement. 



Dr. Mare congratulated the Author on having discovered the 

 relative positions of the Olenellus, Protolenus, and Paradoxides 

 Faunas in the British Cambrian sequence. In the quarry at 

 Comley, which he had visited with Prof. Lapworth, were white 

 and pink crystalline limestones containing Olenellus. These lime- 

 stones were similar to others in various regions exhibiting what 

 Mr. Tiddeman called ' reef-knoll ' structure, although in this case 

 the structure was on a very small scale. 



Prof. Watts said he was glad that the Author had obtained such 

 splendid results from his excavations in Shropshire. It was most 

 interesting to find a representative of the Protolenus Fauna coming 

 hetween the Olenellus and Paradoxides Faunas. 



Mr. Fearnsides, as secretary to the < Excavation of Critical Sec- 

 tions } Committee of the British Association, wished to congratulate 

 the Author on the great success of his trench-digging operations. 

 The discovery of three distinct faunas within a thickness of 6 feet of 

 coarse-textured sediment was of great interest. It drew attention 

 to the sharp contrast between the Lower Cambrian rocks of Shrop- 

 shire and of Merionethshire, and showed that the Comley rocks were 

 much more like the contemporaneous rocks of the Baltic area. 

 The erosion-partings, the minute unconformities hetween successive 

 beds, the limestone pellets associated with phosphatic nodules and 

 glauconitic grains, could all be matched exactly among the Cambrian 

 rocks of Northern Oland, and were there interpreted as distinctive of 

 a period of recurrent alternating deposition and erosion in shallow 

 water of the sea-bed. 



The Author briefly thanked the Fellows for their appreciative 

 reception of his paper, and in reply to Dr. Marr said that the posi- 

 tion of the genus Protolenus at Comley was exactly parallel with 

 that assigned to it by Mr. Matthew in Acadia. He also explained 

 that the paper was only concerned with one preliminary excavation 

 at Comley, and that the further excavations, made under the grant 

 from the Committee for Geological Excavations of the British 

 Association, had yielded results extending to other horizons in the 

 Shropshire Cambrian. To a suggestion made by Mr. Fearnsides 

 he replied that he regarded the grey limestones as shallow-water 

 deposits, possibly laid down in lagoon-like relics of the Olenellus sea. 

 the bottom of which was gradually raised above sea-level to be 

 subsequently eroded by the advance of the, Paradoxides waters. 



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