262 T. Mellard Reade—On the Lower Trias. 



Mr. Hunt's views, we must also be prepared to believe that the 

 bottom is now exactly as it was when first submerged, an opinion 

 in which he will not get many geologists to support him. 



Though not a naturalist, I happen to live on a coast in which the 

 combined action of the wind and tides are continually disturbing 

 the sand banks and the channels and the sandy shore, and thousands 

 of molluscs — I might almost say millions — are dug up during a 

 storm and cast on the shore ; yet sufficient remain to keep up the 

 " breed " so to say. 



If molluscs can live under these conditions in the Estuary of the 

 Mersey, why not in the English Channel ? I may be therefore 

 excused for thinking that their existence in the English Channel 

 proves nothing respecting the tides either one way or the other. 1 



In the Mersey, between Liverpool and Birkenhead, we have a 

 striking instance of the excavating power of the tide. At one point 

 over the Mersey Tunnel, as proved by divers, the rock was bare, with 

 great boulders lying upon it derived from the destruction of the 

 Boulder-clay. It would be wearisome for me to go on multiplying 

 these instances ; suffice it to say that the form of the Mersey bottom 

 is evidently due to tidal rub. 



I have thought it necessary to detail these instances of the effects 

 of tidal action, as, if the tides are physically incapable of producing 

 the effect I attribute to them, viz. the current bedding of sandstones 

 and the rolling of pebbles as seen in our typical Bunter, my theory 

 is invalid. 



As regards Prof. Bonney's criticism, from the known attention he 

 has given to this subject his views no doubt deserve the greatest 

 consideration. I am, however, compelled to say that I fail to see 

 why the Lancashire Bunter, which is of great thickness (proved 

 to 1200 feet), and occupies a large area, should be looked upon as 

 anomalous, and our attention be restricted to conglomerate beds of 

 60 feet in thickness. These beds occur in the Midland Counties, 

 and may have been shore deposits, as suggested by Mr. Jukes-Browne. 

 I expressly said in my last communication that my theory does not 

 exclude shore action. How can there have been seas and embay- 

 ments without shores? 



There are, however, no evidences of littoral deposit in any of the 

 Bunter of Lancashire and Cheshire that I have seen ; and this it 

 was partly the province of my theory to explain. 



It seems, however, I am expected to sketch out the physical 

 geography of the Triassic period, and localize the communications of 

 the Triassic Sea with the Atlantic Ocean. Surely this is making a 



1 Mr. Hunt asks, " "Would Mr. Mellard Reade give his reasons for believing that 

 waves ever cause surface particles in deep water to move in a vertical circle, or an 

 ellipse, not very different from one having the longer axis vertical F " If Mr. Hunt 

 will watch a cork floating in water on which wind waves are generated, he will, I 

 think, see that the vertical oscillatory movement of the cork is as great as or 

 greater than the horizontal. The composition of the two movements will give 

 either a circle or an ellipse. This is no discovery of Mr. Eeade's, but a fact known 

 to every physicist. 



