Mackintosh — Geological Notes on Devon. 299 



Note. — Since the above was written I have found polished circular 

 perforations, of the size of PAoZas-borings, in Stoney Combe, imme- 

 diately to the south of the railway between Newton and Totnes. 

 They generally slant upwards on the protected or over -hanging sides 

 of rocky projections. They are distinct from the vast majority of 

 small deep holes in limestone rocks, which here, as elsewhere, are 

 structural cavities, enlarged, hut never rendered perfectly smooth and 

 circular, by atmospheric action. — CM. 



EXPLANATION OF PLATE XIII. 



Fig. 1. Specimen of perforated limestone from Asheldon, near Torquay (natural size). 

 Fig. 2. Borings from the summit of Kent's Cavern Hill, nearly 260 feet above the 



present sea-level (natural size). 

 Fig. 3. Group of Fholas-horings on part of a block of limestone on the side of 



Asheldon Hill, north of Kent's Cavern, about 190 feet above the sea (about 



one-third the natural size). 



V. — On the Distribution beyond the Tertiary Districts of 

 White Clays and Sands subjacent to the Boulder-clay 

 Drifts. 



By George Maw, F.G.S., etc. 



(Part II.) 



nrWE Pipe-clay beds of Tipperary appear so closely to resemble in 

 character and position the deposits of the Mountain Limestone 

 district of North Wales and North Staffordshire, that it may not be out 

 of place to record some observations made by Mr. C. D, Blake, 

 of Newton Abbot, in 1862, and kindly communicated to me. 

 There are also one or two previously published notices of these 

 deposits, to which reference must be made. 



The first record appears to have been made by Mr. (now Sir 

 Eichard) Griffith, in the form of a report in the minutes of the 

 Eoyal Dublin Society, on the probabilities of finding coal in Tip- 

 perary, a copy of which has been obligingly communicated to me 

 by Dr. Steele ; it is as follows : 



Mr. Griffith says, " Expectations of finding coal were also enter- 

 tained by Lord Waterpark and his tenants on the lands of Scartana, 

 three miles to the south-west of Cahir. In making a well at this 

 place a considerable thickness of disintegrated Chert, a white sili- 

 cious substance, similar in composition to Lydian Stone, was passed 

 through without meeting with any solid rock ; at the depth of 70 feet 

 a black, sooty-like substance, arising probably from the decompo- 

 sition of some vegetable matter, was met with; but as the surrounding 

 country was whoUy composed of Limestone and Lydian Stone with- 

 out the intervention of any other rock, I have no hesitation in stating 

 that the black substance found is not connected with, or likely to lead 

 to the discovery of a bed of coal. So far my examination proved fruit- 

 less, but in exploring the country to the south-east of Cahir, in search 

 of some pits, from which I understood white potter's-clay had previ- 

 ously been raised, I was enabled to trace an extensive and very valu- 



