120 



THE GEOLOaiST. 



of each stratum. The collection is, as our readers well know, arranged on 

 a stratigraphical plan ; and by the use of coloured tablets, in walking past 

 cases we see at a glance the fossils we ought to find in any ordinary lo- 

 cality of every geological formation. To the student this is a facility of 

 the highest value, and enables him, whether studying for a class or pre- 

 paring for a full excursion, to learn with certainty and ease the essentially 

 typical fossils of every stratigraphical group or of the district he is visiting. 



Not a less happy idea was it to illustrate or rather to explain the map- 

 sheets of the Survey, by short memoirs of the geology of the dis- 

 tricts they represent. Thus, the fluvio-marine beds of the Isle of Wight 

 have been described by Edward Forbes ; the country round Chelten- 

 ham, by Mr. Hull ; parts of Wiltshire and Gloucestershire, by Profes- 

 sor Eamsay ; the South StalFordshire Coal-field, by Mr. Jukes ; the War- 

 wickshire Coal-field, by Mr. Howell ; the country round Woodstock, the 

 country round Prescot, in Lancashire, parts of Oxfordshire and Berkshire, 

 and the Wigan Coal-field, by Mr. Hull ; part of Leicestershire, and parts of 

 Northamptonshire and Warwickshire, by Mr. Aveline. The West Indian 

 surveyors have followed this excellent example, and we have had a me- 

 moir on the geology of Trinidad, by Messrs. Wall and Sawkins. 



Two others just issued are before us, ' The Geology of Parts of Oxford- 

 shire and Berkshire (Sheet 13),' by Messrs. Hull and Whitaker ; and ' The 

 Geology of Parts of Berkshire and Hampshire (Sheet 12),' by Messrs. 

 Bristow and Whitaker. _ 



The Geologists' Association are about to take again their summer ex- 

 cursions : how admirably instructive it would be to take one of those geo- 

 logical spots in Berkshire or Hampshire, which Mr. Bristow so faithfully 

 and accurately describes in this little eightpenny Memoir ; and with the 

 geological map of the district, Mr. Bristow's descriptions of the sections 

 and other exposures of the strata, of their order, sequence, and mineral 

 characters, and Mr. Etheredge's lists of fossils, how much more instruction 

 would be got out of some of those pleasant holidays than can ever be at- 

 tainable under the best desultory leadership ! 



In Mr. Hull's ' Oxfordshire' a small coloured geological map is inserted, 

 reduced by photography from the larger Ordnance sheet, so that we have 

 in it map and text for a week's good geological labour. In Mr. Bristow's 

 Memoir, the cretaceous rocks and tertiaries from the Eocene of A¥oolwich 

 and Beading to the alluvium of the Kennet, is treated in a masterl}^ man- 

 ner, and illustrated by well selected woodcuts. The cTetaceous deposits 

 and tertiaries, as also the oolitic series, form the topics of Mr. Hidl's 

 ' Memoir on Oxfordshire and Berkshire,' and, we need scarcely say, are 

 treated in an equally able manner. 



