Dr. H. Woodward — Fossil Insect from Coal-measures. 25 



exposed to the action of land-ice, which has moved over it with more 

 or less damaging effect according to the thickness of that ice. We may 

 consequently infer that the deposition of the clay took place previous 

 to the last general glaciation. Such, it seems to me, is clearly the 

 case with the red clay of Aberdeenshire, and the illustrations of 

 disturbance in the beds at Portobello and elsewhere given by 

 Mr. Geikie in his book convey the same impression. Moreover, such 

 fossil evidence as these clays do present at Errol, Elie, Montrose, 

 and other places points to deeper water than a submergence of even 

 100 feet would imply. I see no reason, therefore, to depart from 

 my opinion that subsequent to the last general glaciation of Scotland 

 there has been no submergence along the eastern side of that 

 country beyond what would be accounted for by a depression of the 

 land, amounting to from about 30 feet on the Firth of Forth to 

 10 feet on the coast of Aberdeen. The history of the Glacial period 

 has proved a difficult subject to unravel, and we have all made 

 mistakes about it. It is therefore in no captious spirit that I have 

 been led to make these strictures on the raised beaches, but rather 

 with the view of promoting a better knowledge of this passage in the 

 last geological changes which our country has undergone. 



Briefly, then, my reasons for disbelieving in the existence of these 

 raised beaches at 50 and 100 feet on the east side of Scotland after 

 the last general glaciation of that country are : — 



1. Because at and below these levels there are moraine heaps 

 which show no evidence of sea-action on them up to such heights. 



2. Because there is an absence of estuary-mud with its 

 characteristic fossils in the valleys at levels where such a sub- 

 mergence should have produced it. 



3. Because there are no beds of littoral shells at levels 

 corresponding to such beaches. 



4. Because the beds of clay supposed to have been formed during 

 the time of the 100 feet beach contain remains of mollusca and 

 starfishes, which indicate deeper water and an older stage of the 

 Glacial period. 



5. Because these clays also show evidence of having been wasted 

 and disturbed by subsequent glacial action, and are therefore 

 anterior to the last general glaciation. 



IV. — A Fossil Insect from the Coal-measures of LongtoNj 



North Staffordshire. 



By Henry Woodward, LL.D., F.E.S., F.G.S. 



SOME time since Mr. John T. Stobbs, F.G.S., obtained a very 

 well-preserved impression in clay ironstone of the wing of 

 a Neuropterous insect from the rich plant-bed at Foley, near 

 Longton, North Staffordshire, which he very obligingly submitted 

 to me for study. The geological horizon is that of the " Peacock 

 Marl " (i.e., the marl overlying the Peacock Coal), and it therefore 

 comes from near the top of the workable Coal-measures.^ 



1 See letter by Mr. John T. Stobbs in Geol. Mag., 1903, p. 524. 



