24 GEOLOGY. 



Mackintosh, D. On the Mode of Occurrence and Derivation of Beds 



of Drifted Coal, near Corwen, North Wales. Quart. Journ. Oeol. 



Soc. vol. xxxii. pp. 451-453. 



The coaly matter occurs in fine gravelly Drift. It probably came 



from the Cefn and Ruabon district, 12 miles E. of Corwen, and was 



transported during an interglacial period when the land was partially 



submerged. This direction of transport is opposite to that of the glacia- 



tion of the district. W. T. 



. New and Extensive Sections of Boulder-clay at Liverpool. 



Geol. Mag. dec. ii. vol. iii. p. 429. 

 Calls attention to section at the new Canada Docks, Bootle. ' 



On the Origin of two polished and sharpened Stones from 



Cefn Cave. Rej). Brit. Assoc, for 1875, Sections, pp. 75, 76. 

 The fragments are limestone ; the author believes them to have been 

 polished by sea-waves, carrying broken ice. 



MacMurtrie, J. On certain Isolated Areas of Mountain Limestone 

 at Luckington and Yobster, in the County of Somerset. Proc. 

 Bath Field Club, vol. iii. no. 3, pp. 287-3Q0 ; 2 plates (map and 

 section). 

 Notes all the facts connected with the mode of occurrence of these 

 limestone-masses, and the several hypotheses that have been suggested 

 to account for their abnormal position in the midst of the Coal Mea- 

 sures. Notices their limited thickness, the lack of positive evidence of 

 faults, and the presence of Coal Measures beneath. Thinks that they 

 have not been upheaved from below, but have been folded over from 

 the main anticlinal of the Mendips. H. B. W. 



Notes on the Physical Geology of the Carboniferous Strata 



of Somersetshire, and associated formations. Pi^oc. Somerset Arch. 



Sf Nat. Hist. Soc. vol. xxi. (n. ser. vol. i.) pp. 41-52. 

 Describes a section from Bath to Chewton Mendip, and points out 

 the general divisions of the Coal Measures, their relations with the 

 overlying rocks, and their geographical outline ; with some remarks on 

 possible areas of Coal Measures beyond the known coal-fields. Eefers 

 to the elevation of the Mendip anticlinal, and the results thereby pro- 

 duced on the neighbouring coal-field, as shown in the folded strata of 

 Yobster and the overlap or side-fault of Eadstock. Remarks upon the 

 denudation of the district, and gives estimates of the amount of rock 

 removed. H. B. W. 



Marr, J. E. Fossiliferous Cambrian Shales near Caernarvon. Quart. 

 Journ. Geol. Soc. vol. xxxii. pp. 134, 135. 



The shales extend from about 3 miles S.W. of Caernarvon to Bangor, 

 nearly parallel to the Menai Straits ; they are faulted against L. Cam- 

 brian to the E., and they disappear against a greenstone dyke on the 



