38 Hecieics — Geohgy of Andocer. 



or shale above and not in the coal itself; and these, although other- 

 wise very similar to the coal balls, were formed under conditions less 

 free from detrital matter, as they contain from 1 to 6 per cent, of 

 silicate of alumina. 



The main conclusions are that (1) the coal balls were formed in the 

 position in which they are now found, and probably also the coal itself 

 was likewise formed in situ ; (2) the sea water was fundamentally 

 important during the coal ball formation in acting both as a temporary 

 preservative and as the source of the calcium and magnesium 

 carbonates required for petrifaction; and (3) the plants in the roof 

 nodules represent a different flora from that found in the coal. 



The conditions under which these phenomena were produced are 

 to be found in the mangrove swamps to-day, where " Groves of large 

 trees with smaller herbs and ferns finding place between and around 

 their stems grew in the flat swampy levels between the higher ground 

 and the sea". 



The authors give an interesting word-picture of the features 

 attending the formation of the coal balls, Avhich are ' ' relics of a 

 forest which grew quietly in a swamp in the place where they are 

 now found, while the plants in the shales and in the roof nodules 

 above had drifted out to sea from other districts and bear in the 

 character of their structures the impress of the different type of land 

 on which thev lived ". 



V. — The Geqlogy of the Countky aeouxd A^'DovER. By A. J. 

 Jukes-Browne, B.A., F.G.S. ; partly from notes by F. J.- Bennett, 

 F.G.S., and H. J. Osborne White, F.G.S. pp.' v, 67, with 12 

 text-illustrations. Price Is. Qd. Colour-printed map. Sheet 283, 

 Is. %d. 

 The Geology of the Country around Henley -on -Thames and 

 Wallingfoed. By A. J. Jukes-Browne and H. J. Osborne White. 

 pp. vii, 113, with 13 text-illustrations. Price 2s. Colour-printed 

 map. Sheet 254, price Is. 6^. 



IN the memoir ou Andover we have a description of a large Chalk 

 area which extends from the eastern borders of Salisbury Plain 

 near North Tidworth, through Andover and Whitchurch to Overton. 

 On the northern margin are included the eastern end of the Vale of 

 Pewsey, and the famous 'Valley of Elevation' of Burghclere and 

 Kingsclere, an inlier of Upper Greensand Avith steeply inclined Chalk 

 on the north bounding a tract of the Eocene strata of the London 

 Basin. 



The greater portion of the work is occupied with an account of the 

 stratigraphy and paljeontological zones in the Cretaceous rocks, and 

 here Mr. Jukes-Browne acknowledges aid given by Mr. C. Griffiths, 

 of Winchester, and Mr. B. M. Brydone, who have zealously worked at 

 the fossils in the Chalk. The Eocene strata include Beading Beds and 

 higher divisions up to the Bracklesham Beds seen at Highclere. Clay 

 with flints and other superficial deposits are likewise described, but we 

 find no reference to the Palaeolithic implements of St. Mary Bourne, 



