286 Correspondence — Mr. H. B. Woodward. 



of muddy sand, below 70 feet of surface and Bonlder-clay, in sink- 

 ing a pit 2^ miles west, or down the valley, from the above quarry. 

 The tusk was broken up and destroyed, the workmen mistaking it 

 for wood ; a fragment was procured and lodged in the Hunterian 

 Museum, Glasgow, for preservation. The shells were identified by 

 Mr. John Young, F.Gr.S., of this museum, as follows : — Astarte com- 

 pressa, Cyprina Islandica, Fiisus ? a fragment, Mya truncata, Nucula 

 tenuis, Tellina balthica, Natica Grcenlandica, Turritella terehra. 

 Some of these, and other fragments of shells found, had a water- 

 worn appearance. The section taken downwards is as follows : — 

 surface and Boulder-clay 78 feet, muddy sand, the mud and sand 

 finely laminated in alternate layers, about two feet, soft sand one 

 foot, gravelly sand (fossiliferous) 20 feet, resting on the Carbon- 

 iferous strata. This section is interesting, by throwing light upon 

 the position, and age, of these fossiliferous beds, as well as evidence 

 of their extent. Dr. Brj^ce makes them Pre-Glacial, and of the age 

 of the Upper Crag (Quarterly Journal, vol. xxi. p. 213). From an 

 examination of the rock specimens in the 20 feet bed of sand under- 

 lying the fossiliferous beds, they are largely made up of erratics, 

 highland schists, gneiss, granite, Old Eed Sandstone, quartz, etc. 

 These erratics are greatly in excess in this bed of sand, to what 

 they are in the Boulder-clay of the district, that overlies the fossil- 

 iferous beds. At one time I made a minute examination of the rocks 

 in the Boulder-clay of this district, and found the erratics small, 

 about 4: per cent. ; but in this bed they are nearly 30 per cent, of the 

 whole rock contents. This is certainly against the Pre-Glacial age 

 of the beds. R. Craig. 



Langside, Beith. 



THE DISTURBANCES AT VOBSTER IN SOMERSET. 



Sir, — The announcement of the discovery of Millstone Grit at 

 Vobster, made in your last Number by the Eev. H. H. Win wood, 

 is so interesting that I hope he will give further particulars, and 

 publish a section of the facts observed. In my diagram-section 

 (Geol. Mag. Vol. VTII. p. 153) I have inserted the Millstone Grit 

 at Upper Vobster, but not at Lower Vobster (to which Mr. Win wood, 

 I presume, refers) : its presence at this latter place will simplify the 

 explanations, and dispose of one argument against the " overthrow 

 theory." To that theory, which supposes that the Limestone masses 

 of Vobster were portions of rocks " squeezed together, thrown up, 

 and finally folded over from the main ridge " {i.e. the Downhead 

 Anticlinal), my chief objection is that I can discern no evidence in 

 the structure or lie of the Lower Carboniferous rocks and Old Eed 

 Sandstone to favour the notion. Why not take into account the 

 ascertained structure in these hard and well-marked rocks, and not 

 rely simply on the evidence in the neighbourhood of Vobster, where 

 in the comparatively soft and yielding Coal-measures (to quote the 

 words of Mr. McMurtrie) "we find an amount of confusion and 

 distortion which, literally bafifies description " ? 



We have actual evidence of a faulted-anticlinal at Penhill House, 



