8o PROC. COTTESWOLD CLUB vol. xiii. (2) 



the ancestors of the world's inhabitants. I have been 

 searching these rocks at intervals for the last 20 years ; 

 and I have been in the habit of urging upon younger 

 workers that a fortunate discovery of fossils in these 

 strata might be of the very first importance in the history 

 of geological and biological science. Hitherto, however, 

 our researches have been tantahsing in the extreme ; for, 

 though we have obtained evidence that the life of the 

 Longmyndian period was by no means meagre, we know 

 very httle of its nature. 



The Longmyndian series in the typical area consists of 

 conglomerates, purple and green sandstones, and fine- 

 grained shaly and slaty rocks. Their thickness was 

 calculated by the Government Surveyors at not less than 

 five miles. Making allowance for probable repetitions, 

 we may adopt a minimum estimate of three miles, whereof 

 at least one-third is composed of strata which were once 

 a fine mud, a material above all others most favourable 

 for receiving and retaining impressions made upon it. It 

 is in such rocks as these that we find the exquisite plant 

 remains of the Coal Measures and the exceptionally 

 perfect ammonites of the Middle Oolite. Nor have these 

 shales undergone any material change. They are in- 

 durated and somewhat slightly cleaved, l)Ut they usually 

 split along the [)lanes of lamination, and readily reveal 

 such traces of fossil remains as they contain. 



When the Geological Survey first studied the Long- 

 mynd rocks, they described them as " unfossiliferous." 

 Subsequently, Mr Salter discovered what he regarded as 

 the pygidium of a trilobite which he named Palcpopyge 

 Ramsayi. This marking must, however, be relegated to 

 the limbo where Eozoon Canadense is already peacefully 

 reposing. Salter's discovery of Arenicolites is, however, 

 abundantly confirmed. It occurs in the form of small 

 pits, which Salter supposed to be the orifices of borings 



