122 Reviews — Bry doners Chalk of Hants. 



I. — The Stratigraphy of thk Chalk of Hants. With Map and 

 Palaeontological jSTotes. By R. M. Brtdone, ii'.G.S. 8vo ; 

 pp. 1-116, with 3 plates and coloured map. London: Dulau 

 and Co., 1912. Price 10.s. 6d. net. 



ri1HE publication of this work, comprising the results of research 

 J_ extending over more than twenty years, provides a notable 

 addition to the literature of the Chalk zones. At the onset we must 

 congratulate Mr. Brydone on the completion of the truly prodigious 

 work of zoning 1,052 exposures of Chalk in Hampshire. He has 

 succeeded, moreover, in producing from his results a very fine zonal 

 map on the 1 inch scale, clearly a task beset with many difficulties. 



Treatises on the Chalk of Hampshire, as Mr. Brydone remarks, 

 are not numerous. On this account we could wisli that in his brief 

 bibliographical notes he had referred, as in a previous publication, 

 to the excellent work on Chalk geology carried on since pre-zonal 

 days bv the Winchester College Natural History Society. Its latest 

 publication ' (issued since the appearance of Mr. Brydone's book), 

 dealing with the various divisions of the Chalk, and giving 

 lists of fossils and sketch-maps, affords a conspectus of the Chalk 

 round Winchester that could not fail to be of great value to 

 any student unable to consult more compendious essays. The 

 present volume must be regarded as an amplification and 

 completion of the previously published work by the author and 

 Mr. Griffith on The Zones of the Chalk in Hants. As regards some 

 views and terminology therein adopted, Mr. Brydone in his first 

 chapter suggests sundry modifications. His researches have brought 

 forward manv interesting points in connexion with the rmicronata 

 zone, which, bj- the way, has been discovered in a new district near 

 Dean. It is found that in Hampshire the ranges of Beleinnitella 

 mucronata and Actinocamax qiiadratus are commerged for at least 

 20 feet, the advent of the former coinciding with the appearance 

 of marl. As Mr. Brydone says, "the general result is to administer 

 ... a severe shock to the doctrine of the infallibility of B. viticronata 

 as a zonal guide." 



Some changes are made with respect to the quadratus zone. It is 

 proposed that the sub-zones of Offaster 2iil'U'la and Echinocorys sciitatus, 

 var. depressus, should be separated under the name of the zone of 

 0. pilula, but that this should still be divided into the sub-zones of 

 abundant 0. pilula and E. scutatus, var. depressus. The familiar 

 Rhi/ncho?iella cHvieri has disappeared without apology or explanation 

 from the zonal terminology in this book, Inoceramus lahiattis being 

 used instead as the index-fossil. 



It may be highly desirable and may constitute an advance on the 

 lines of present research to establish sub-zones (each in itself, of 



' Geological Notes on the Chalk of Hampshire, with Hints to Collectors, 

 by C. Griffith, M.A., F.G.S. 43 pp., with sketch-maps. Published by the 

 Winchester College Natural History Society, 1912. 



