4 A Retrospect of G eoJotjy for Fortij Years. 



Bolt Head are dealt with by A. K. Hunt, and he is not suffered by 

 Bonney to go free from criticism. 



Eozoon again comes up, Sir J. W. Dawson making one more 

 appeal in favour of its organic origin. 



Callaway deals with Archeean. The ' Mouian ' system of J. F. 

 Blake is also discussed, and Hughes writes on the Cambrian of 

 North Wales. 



Notable are the articles by Lapworth on the Close of the Highland 

 controversy, on the Cambrian rocks of Nuneaton, and on the 

 Olenellus Fauna in Britain. He likewise defines his Ordovician 

 System, and writes on the Ballantrae rocks. Nicholson and Marr 

 deal with the Lower Palceozoic rocks of the Lake District. 



The Culm-measures of Devonshire, Coal in the south-east of 

 England, the Trias, the Neocomian, and the Bagshot Beds come in 

 for a good deal of attention. 



A. Harker, as well as T. H. Holland, appears on the scene, and 

 they, together with G. A. J. Cole, describe various igneous rocks ; 

 while Judd writes on the lavas of Krakatoa, and Teall on the Cheviot 

 quartz-felsites and augite-granites. 



The mineralogical constitution of calcareous organisms forms tlie 

 subject of an important paper by V. Cornish and P. F. Kendall. 

 Pisolite is dealt with by Wethered ; explosive slickensides by 

 Strahan ; Earthquakes, the creeping of soil-cap, and the stone-rivers 

 of the Falkland Islands by Davison; Dust and Soils by C. Eeid ; 

 while W. M. Hutchings writes on Slates and fire-clays. Landscape 

 Marble, the flexibility of rocks, faults, jointing, and cleavage also 

 receive consideration, Howorth continues to write on the Mammoth 

 and the Glacial Drift ; others deal with the Caves of North Wales, 

 and with Moel Tryfaen, while Geological Time, the permanence of 

 Continents, and geological nomenclature attract several writers. 



In the Fourth Decade the life -zones of Carboniferous and 

 Cretaceous rocks are specially dealt with, while those of earlier 

 and later date come in for a certain amount of discussion. The 

 zones of the Carboniferous system had been neglected, but Marr^ 

 Garwood, and Wheelton Hind come to the rescue, and it is well 

 known that Traquair and Kidston are also keenly interested in the 

 subject. The admirable work of A. W. Eowe on the Chalk zones 

 is reviewed, and Jukes-Browne discusses the possibility of making 

 ' chronological maps,' which no one has yet attempted except on 

 a small scale or in a general way. 



The nomenclature of Igneous rocks is discussed by H. Stanley 

 Jevons, and the new American classification is criticized without 

 favour. The order of consolidation of minerals in igneous masses 

 receives attention from Sollas, while Harker describes the sequence 

 of igneous rocks in Skye. Greenly gives accounts of various 

 Anglesey rocks ; Bonney and Miss Kaisin deal with rocks from 

 Kimberley in Cape Colony, Teall with Nepheline-syenite from 

 north-west Scotland, McMahon with the granite of the Himalayas, 

 and A. E. Hunt with that of Dartmoor. J. Parkinson and H. J. 

 Seymour describe sundry igneous rocks. Hutchings discourses on 



