BRITISH ISLES, 37 



brown water- worn sandstone masses, which last often contain casts of 

 shells, that are disclosed by a sharp blow ; and it is now concluded that 

 these stones are the remnants of a deposit older than theCoralline Crag, 

 to which they were once thought to belong. The peculiar Suifbjjv 

 formations. Coralline and Red Crags, with their chief sections, arc 

 noticed, and followed by accounts of the Norwich Crag, Chillesford Clay, 

 and Forest-bed, a description of the sandy gravels and clays of the 

 Lower and Upper Glacial Drifts and of the Post-Glacial beds conclu- 

 ding the essay. W. W. 



Taylor, J. E. Underground Explorations. Cassell's Mag. part Iv. 



pp. 67-72. 

 A description of the Sub- Wealden Boring. 



. A Submarine Forest in the Orwell. Science Gossip, no. 120, 



p. 278 (and Local Papers). 



A notice of a bed of peat, with leaves and trunks of trees, teeth of 

 Mammoth, and freshwater shells, found in deepening part of the channel 

 of the estuary of the Orwell, a little below Ipswich. W. W. 



Thomas, D. The Avon Valley Mineral District. Discussion. Proc. 



S. Wales Inst. Eng. vol. viii. no. 5, pp. 197-206. 

 The author submitted analyses of the coals by Mr. J. Napier ; and a 

 discussion ensued on the faults and anticlinal. 



Thomson, James. On the Stratified Eocks of Islay. Trans. Geol. 

 Soc. Glasgow, vol. iv. part iii. pp. 313-315. (Abstract only.) 



, and Catjnter, Henry. On the Geology of Lewis. Trans. Geol. 



Soc. Glasgow, vol. iv. part iii. pp. 315, 316. (Abstract only.) 



TopLEY, W. On the Correspondence between some Areas of Apparent 



Upheaval and the Thickening of Subjacent Beds. Quart. Journ. 



Geol. Soc. vol. XXX. pp. 186-194 (woodcut). 



The Socondarj^ rocks often thin out in particular directions ; it was 



shown that this must have some effect on the dip of the beds which 



overlie the particular rocks. Where a whole series of rocks thin in 



one direction, the sum of the thinning of these rocks will often account 



for the whole of the dip of overlying rocks. These statements were 



illustrated by examples of rocks which dip towards geological basins. 



As regards the beds contained within the basins, it was shown that 



they often thicken with the dip, or towards the centre of the basin. 



W. T. 



. Geological Report on the Sub-Wealden Exploration. Rep. 



Brit. Assoc, for 1873, pp. 491-495. 



Gives a detailed section from the surface to 294 feet. Notes are 

 given of the classification of the Wealden beds and the new light thrown 

 on this subject by the boring. 



. The Sub-Wealden Exploration. Trans. N. Engl. Inst. Eng. 



vol. xxiii. (part vi.) pp. 185-188. 

 A brief account of the boring and of the beds traversed. 



