Denbighshire Series of South Denbighshire. 141 



Details of their structure are given; and the author states that he 

 is inclined to regard them as a group of bedded acid lavas and tuffs, 

 crossed by three bands of dolerite. What little balance of evidence 

 there is seems to be in favour of the intrusive character of the 

 dolerites. No true limestones have been found, and the only very 

 calcareous rock seen is regarded as a rock belonging to the volcanic 

 group which has been largely calcified. 



Somewhat similar rocks are found on the southern part of Ragged- 

 stone Hill, and a shattered felstone occurs forming an isolated boss 

 south of Chase End Hill. 



Several hypotheses present themselves as to the relationship be- 

 tween the Warren House Rocks and the Crystalline Schists. The 

 former may be distinct from the latter, in which case the absence of 

 mechanical deformation would indicate that they are younger. If 

 we consider that the Malvern Schists have been formed out of 

 volcanic rocks by dynamic metamorphism, the Raggedstone Hill 

 rocks may be a portion of the volcanic complex which has under- 

 gone only partial transformation, whilst the Warren Hill rocks have 

 altogether escaped metamorphism, the crystalline schists repre- 

 senting its final stages. 



2. ' The Denbighshire Series of South Denbighshire.' By Philip 

 Lake, Esq., M.A., F.G.S. 



The area to which this paper chiefly refers is the south-western 

 quarter of the Llangollen basin of Silurian rocks. The beds are 

 here very little disturbed, and the sequence is readily made out. 

 The following subdivisions are recognized (in descending order) : — 



Leintivardinensis-slsLtes ; with Monograptus leintivardinensis. 

 Upper gritty beds ; with no fossils known. 

 Nantglyn flags ; with M. colonus, Cardiola, &c. 

 Moel Ferna slates ; with M. priodon, M. Flemingii. 

 Pen-y-glog grit. 



Pen-y-glog slate ; with M. personatus, M. priodon, Retiolites 

 Geinitzianus, &c. 



Farther east the fossiliferous beds of Dinas Bran appear to lie 

 considerably above the Leintivardinensis- slates. 



On comparison with other areas it is found that this succession is 

 almost identical with that in the Long Mountain, in North Denbigh- 

 shire, and in the Lake District. It is also inferred that the 

 Leintwardinensis-slates represent the Leintwardine Flags of Here- 

 fordshire, and that the Dinas Bran beds correspond with a part of 

 the Upper Ludlow. 



3. ' On some Points in the Geology of the Harlech Area.' By 

 the Rev. J. F. Blake, M.A., F.G.S. 



In testing the conclusions arrived at in regard to the Llanberis 

 and Penrhyn area by an examination of that of Harlech, two 



