Chronolgical Value of the Pleistocene Deposits of Devon. 233 



2. "Contributions to the history of the Deer of the European 

 Miocene and Pliocene Strata." By Prof. W. Boyd Dawkins, M.A., 

 F.R.S., E.G.S. 



3. " On the occurrence of Branchipus (or Chirocephalus) in a 

 fossil state, associated with ArcTiceoniscus, and with numerous Insect- 

 remains in the Eocene Freshwater Limestone of Gurnet Bay, Isle of 

 Wight." By Henry Woodward, Esq., P.R.S., E.G.S. 



4. " The Chronological Yalue of the Pleistocene Deposits of 

 Devon." By W. A. E. Ussher, Esq., E.G.S., of H.M. Geological 

 Survey. 



In this paper the author endeavoured to work out the sequence of 

 events indicated by the Pleistocene deposits of Devonshire. He 

 believed that during late Tertiary times subsidence extended to the 

 south-western counties ; and to this he ascribed with some doubt 

 the accumulation of a patch of gravel on the north summit of the 

 Black Downs and of part of the old bone-breccia of Kent's Cavern. 

 In the Glacial period, with the increase of cold, snow accumulated on 

 the high lands, with formation of glaciers, which descended and 

 united to form a great ice-field, planing the surface of a district 

 composed chiefly of Cretaceous and probably Tertiary strata. To 

 this period the author ascribed the formation of the clay with 

 unworn fragments of flint and chert, and, doubtfully, part of the 

 clays of the Bovey valley, the clay of Petrockstow, and part of the 

 bone-breccia and the crystalline stalagmite of Kent's Cavern. The 

 Postglacial phenomena he referred to three subperiods, in the first of 

 which, during a gradual amelioration of the climate and disappear- 

 ance of the ice, large quantities of surface-water were set free, 

 redistributing and removing Tertiary outliers, partially destroy- 

 ing the old ice-beds and moraine rubbish, and sweeping Secondary 

 deposits from Palaeozoic districts. The deposits then formed were 

 supposed to be the old gravel patches of Colford and Orleigh Court, 

 the waterworn materials on the Blackdowns and Haldon, the sands 

 flanking the Bovey valley, and, with doubt, the redistributed 

 Triassic pebble-beds of Straightway Hill, and part of the cave-earth 

 of Kent's Cavern. The next subperiod he regarded as one of great 

 fluTiatile action, the land being higher than at present, though 

 sinking, and the meteorological conditions such as to greatly increase 

 the volume of the rivers. The subsidence having continued to the 

 level of the present raised beaches, reelevation took place, producing 

 greater cold and more extreme seasons, and culminating in the 

 production of continental conditions, permitting the southward mi- 

 gration of a temperate fauna, and the advent of one requiring 

 greater cold. During this period the gravels connected with the 

 formation of the present valley-system, the raised beaches, and the 

 " Head" were produced, and, doubtfully, part of the cave-earth and 

 the granular stalagmite of Kent's Cavern, and the clay of Petrock- 

 stow and Eoundswell. In the last subperiod the author considered 

 that a subsidence took place, during which most of the valleys were 



