90 Renews — Proceedings of Chester Natural Science Society. 



for Cheshire Geologists." The paper is an abstract of one read 

 before the Society, Nov. 27th, 1878. Professor Judd shows that 

 the strata of the various formations were originally much more 

 widely distributed over the British Islands than they are at the 

 present day, and that the breaks in their continuity must have 

 been caused by subsequent denudation. Not only is this true in 

 the case of the older Carboniferous rocks. It is probable that 

 before the deposition of the Tertiary rocks, the greater part of 

 the British Islands was " buried under the thick strata of the 

 Liassic and Oolitic age, and that a great winding sheet of Chalk 

 enveloped nearly the whole of the country." The greater part of 

 the Secondary strata has now been removed by denudation, and 

 much interest naturally attaches to these isolated patches or " out- 

 liers." One such patch is in the district lying between Audlem and 

 Wem, and the problem for Cheshire geologists, writes the Professor, 

 is — (1) To determine the exact extent and limits of the outlier. 

 (2) The relations to the surrounding strata. (3) The nature, thick- 

 ness, and fossil contents of the outlier. We hope Cheshire geologists 

 are now on their way at least to the solution of this geological 

 problem. 



We now come to a very short note on "Traces of an Interglacial 

 Land-surface at Crewe," by that veteran geologist Mr. D. Mackintosh, 

 F.G.S. These traces the author supposes he has found in an exceed- 

 ingly fine and more or less flexible kind of leaf-clay which he 

 discovered at the Crewe Eailway Station. 



The next paper is one by Mr. W. Shone, F.G.S., on " The Silting- 

 up of the Biver Dee : its Causes." As an introduction to his 

 paper, Mr. Shone first gives us some account of the river both in 

 historic and in prehistoric times, with some interesting quotations 

 from early writers. Then follow a number of details — the result of 

 much patient observation — as to the rate of flow of the tide up 

 the river, and its rate of outflow back again to the sea. Mr. Shone 

 attributes the silting-up of the river to several causes combined, the 

 chief of which are — the tapping of the water at Llangollen for the 

 canal ; the building of the causeway, and the reclaiming of the land 

 on Sealancl. We cannot help thinking that, after all, the real cause 

 of the silting-up of the Dee is the extremely small amount of fresh 

 water which comes down from Bala Lake. We know that in dry 

 seasons, with the exception of a small quantity of water which passes 

 over the mill, no water at all finds its way over the Causeway, 

 and of course there would be just the same flow so far as volume is 

 concerned, whether the Causeway were there or not. But the upper 

 part of the river instead of being practically a long lake would be a 

 shallow muddy river, were the Causeway removed. 



Three papers follow by Mr. A. 0. Walker, the first two on ento- 

 mology and the third on a meteorological subject. Tbe first, on 

 " Climatic Causes affecting the Distribution of the Lepidoptera in 

 Great Britain." The second is " A List of the Macro-lepidoptera of 

 the District." The third by Mr. Walker is on the " Climate of the 

 Cheshire District in Belation to Fruit-growing." 



