106 Mr. Tate on the Geology and Archceology of Beadnell. 



Besides the forms now described there are other casts and 

 trails at Beadnell. Some seem to be the burrows or casts of 

 annelids, passing either perpendicularly or obliquely through 

 several layers of rock, the upper surface of the layers being 

 pitted and the under projecting. These casts or burrows are 

 about two lines in diameter, and are so crowded together in 

 some rocks both at Beadnell and Kirkwhelpington as to give 

 the stone a pock-marked appearance. Meandering furrows 

 about one line in width with a ridge in the centre are probably 

 the trails of an annelid : they occur also at Howick, North 

 Sunderland, and Haltwhistle. It has been suggested that 

 these were tracks made by small crustaceans, but the absence 

 of all remains of the hard shell renders this opinion doubtful. 



More extended observations on these borings and trails and 

 on other markings associated with them, are required before 

 their characters can be distinctly determined. 



As confirmatory of the marine conditions of the rocks in 

 which the ripple marks and annelids are found, I may add, 

 that the Haggy sandstone containing annelids at Howick has 

 in some of the layers Bellerophon^ Euomphalus, Murchisonia 

 and Pleurotomaria^ shells undoubtedly of marine origin. 



The group of facts now noticed gives us a partial glimpse 

 of a far distant Era. The Beadnell flaggy beds expose to our 

 view an ancient coast line ; we hear the waves breaking on the 

 shore ; we perceive currents rolling along masses of sand ; the 

 tide recedes and ripple marks — long ridges and furrows sharp 

 and distinct appear ; and there too are seen worms, some of 

 large size, crawling over the surface or burrowing in the sand. 

 Marks left by the sea are often fugitive — the impressions 

 made by one tide are obliterated by another ; but here they 

 are preserved ; the sand and mud are hardened, it may be by 

 a warm sun breaking forth and baking the surface before the 

 return of the tide ; other deposits cover over the markings 

 and bury up and preserve the organic forms ; and now, when 

 these rocks are laid bare and examined, they reveal to us, that 

 the same physical laws operated during the Carboniferous Era 

 as at the present time, and that, though the aspects of 

 vegetation might be wonderfully different, and organic life 

 specifically distinct, yet the animals of the period were formed 

 according to the same type and were subject to the same con- 

 ditions as those now existing. 



Before leaving the stratified rocks, allusion may be made 

 to the illustration they afford of changes of condition and of 

 oscillations of level. Taking the coal in connection with the 

 limestone, there is evidence of not less than fourteen changes 



