374 Reviews — The Geological Survey. 



great South Wales coal-field has been nearly completed; and that the 

 survey of West Cornwall, including the Lizard area, has been finished. 

 In the Midland district the survey of the Derbyshire and Nottingham- 

 shire coal-field has been carried northwards towards the borders of 

 Yorkshire. In Scotland work has been continued in the Northern, 

 Central, and Western Highlands, including portions of Caithness and 

 the island of Mull, while progress has been made with the re-survey 

 of the coal-fields. 



Among the points of special interest to which the Director, Dr. Teall, 

 calls attention, is the evidence of certain * fold-faults ', which have 

 been found to occur in the neighbourhood of Glen Etive, Loch Leven, 

 and Glen Nevis. These are recumbent folds more or less dislocated, 

 and in certain cases subsequently rucked up and involved in other 

 isoclinal folds, whereby the task of the geological surveyor becomes 

 about as difficult as it well can be. In South Wales the oldest 

 Cambrian strata, referred to the Caerfai group of Dr. Hicks, have been 

 proved to rest unconformably on pre-Cambrian rocks. Attention has 

 been given to the marine bands, first described by J. W. Salter, in the 

 Old Eed Sandstone of West Angle Bay in Pembrokeshire. They are 

 regarded as representing temporary incursions of the sea into the 

 area prior to and foreshadowing the marine conditions of the Lower 

 Carboniferous. 



Observations on the coals of Lanarkshire point to the conclusion 

 that the lateral change from bituminous coal to anthracite is in some 

 way connected with original differences in composition, as was 

 suggested in reference to the coals of South Wales, recently described 

 in a Survey Memoir. 



In the Petrographical department investigations have been made 

 on the felspathic hornstones from the aureole of the St. Austell 

 granite, and on nepheline rocks from the midland valley of Scotland. 



In the Palseontological department attention has been given to the 

 species of Productus found in the Carboniferous rocks, with the view 

 of defining forms that characterize the zonal subdivisions in the 

 Limestone Series. We are glad to learn that a memoir is in 

 preparation on the Secondary formations proved in some of the deep 

 borings in Kent. Prom the preliminary notices we learn that the 

 Hastings Beds at Dover rest on an irregular surface of Kimeridge 

 Clay, and that the lowest bed of the Lower Lias, which rests directly 

 on Coal-measures at Dover, belongs to the Caprieornus zone. Else- 

 where at Brabourne it appears that the Lower Lias rests directly on 

 Triassic marls, without any evidence of intervening Rhsetic beds. 



The Appendix contains an article " On a Boring in the FuUonian 

 and Inferior Oolite at Stowell, Somerset", by Mr. John Pringle, who 

 obtained a very interesting series of fossils. They indicate that the 

 Lower Pullers Earth clay should be grouped with the Inferior Oolite 

 Series, and the Pullers Earth rock and overlying clay with the 

 Great Oolite Series. 



There is a second article *' On the Stratigraphical Position of the 

 Achanarras Pauna in the Old Red Sandstone of Caithness ", by 

 Mr. R. G. Carruthers. The Achanarras fauna occurs near Spital, to 

 the south of Thurso, and was originally described by Dr. Traquair as 



