﻿Geological 
  Society. 
  3G3 
  

  

  True 
  S. 
  cuscinus 
  occurs 
  in 
  the 
  upper 
  parts 
  of 
  tlie 
  Ucayali 
  

   and 
  Madre 
  de 
  Dios 
  Rivers, 
  considerably 
  further 
  to 
  the 
  north- 
  

   west 
  than 
  this 
  Bolivian 
  representative 
  of 
  the 
  species. 
  The 
  

   general 
  colour 
  of 
  the 
  under 
  surface 
  is 
  on 
  tlie 
  average 
  markedly 
  

   more 
  ochraceous 
  in 
  the 
  south-eastern 
  form. 
  

  

  PROCEEDINGS 
  OF 
  LEAllNED 
  SOCIETIES. 
  

  

  GEOLOGICAL 
  SOCIETY. 
  

  

  August 
  8th, 
  1913.— 
  Dr. 
  Aubrey 
  Strahan, 
  F.R.S., 
  President, 
  

   in 
  the 
  Chair. 
  

  

  The 
  following 
  communication 
  was 
  read 
  : 
  — 
  

  

  * 
  The 
  Miocene 
  Beds 
  of 
  the 
  Victoria 
  Nyanza 
  and 
  the 
  Geology 
  of 
  

   the 
  Country 
  between 
  the 
  Lake 
  and 
  the 
  Kisii 
  Highlands.' 
  By 
  

   Felix 
  Oswald, 
  D.Sc, 
  B,A., 
  F.(t.S. 
  ; 
  with 
  Appendices 
  on 
  the 
  Vei-te- 
  

   brate 
  Remains, 
  by 
  Charles 
  William 
  Andrews, 
  D.Sc, 
  F.R.S. 
  ; 
  on 
  

   the 
  Non-Marine 
  Mollusca, 
  by 
  Richard 
  Bullen 
  Newton, 
  F.G.S. 
  ; 
  and 
  

   on 
  the 
  Plant- 
  Remains, 
  by 
  Misa 
  N. 
  Bancroft, 
  B.Sc, 
  F.L.S. 
  

  

  The 
  Miocene 
  beds 
  of 
  the 
  eastern 
  coast 
  of 
  the 
  Victoria 
  Nyanza, 
  

   south-east 
  of 
  Karungu, 
  form 
  a 
  narrow 
  zone 
  (covered 
  with 
  blact 
  

   earth) 
  at 
  the 
  foot 
  of 
  cliffs 
  of 
  overlying 
  nepheline-basalt, 
  and 
  are 
  

   only 
  exposed 
  in 
  a 
  few 
  gullies. 
  The 
  whole 
  series 
  is 
  conformable, 
  

   dipping 
  8° 
  north 
  by 
  west, 
  

  

  1. 
  (Beds 
  1-12.) 
  An 
  upper 
  group 
  (about 
  70 
  feet 
  thick) 
  of 
  grey 
  

   and 
  brown 
  clays 
  and 
  shales, 
  with 
  occasional 
  current-bedded 
  sand- 
  

   stones 
  containing 
  terrestrial 
  shells 
  (Tropidophora, 
  Cerastus), 
  as 
  

   also 
  calcified 
  tree-stems 
  in 
  the 
  uppermost 
  bed, 
  

  

  2. 
  (Beds 
  13-25.) 
  A 
  middle 
  group 
  (about 
  30 
  feet 
  thick) 
  of 
  red 
  

   and 
  grey 
  clays, 
  with 
  white 
  sandstones 
  in 
  the 
  lower 
  half. 
  No 
  bone- 
  

   bed, 
  but 
  fragmentary 
  Chelonian 
  and 
  Crocodilian 
  remains 
  occur 
  

   sparsely 
  throughout 
  the 
  series. 
  Persistent 
  horizons 
  are 
  a 
  traver- 
  

   tinous 
  marlstone 
  (No, 
  14) 
  containing 
  AmpuUaria 
  and 
  Lanisies 
  ; 
  

   a 
  thin 
  sandstone 
  (No. 
  16) 
  yielding 
  Hyracoid 
  jawbones 
  ; 
  and 
  a 
  gravel 
  

   (No, 
  24) 
  yielding 
  teeth 
  of 
  Dinotherium^ 
  Frotopterus, 
  crocodile, 
  etc, 
  

  

  3. 
  (Beds 
  26-37,) 
  A 
  lower 
  group 
  (about 
  35 
  feet 
  thick) 
  of 
  current- 
  

   bedded 
  sandstones 
  and 
  gravels 
  passing 
  down 
  into 
  clays 
  and 
  marl- 
  

   stones, 
  A 
  conglomerate 
  of 
  calcareous 
  nodules 
  overlies 
  gravelly 
  

   sandstones 
  (No, 
  31) 
  containing 
  isolated 
  bones 
  of 
  Dinotherium, 
  

   Authracotheroids, 
  rhinoceros, 
  giant 
  tortoises, 
  etc., 
  indicating 
  a 
  

   Lower 
  Miocene 
  (Burdigalian) 
  age, 
  with 
  Amjpullaria, 
  Cleopatra, 
  

   and 
  terrestrial 
  shells 
  {Cerastus). 
  

  

  These 
  fiuviatile 
  sediments 
  were 
  deposited 
  in 
  a 
  lagoon, 
  and 
  were 
  

   derived 
  from 
  gneisses, 
  andesites, 
  and 
  quartzitea 
  that 
  still 
  occur 
  

   in 
  situ 
  to 
  the 
  eastward. 
  Calcareous 
  springs 
  acted 
  intermittently, 
  

   and 
  the 
  sediments 
  became 
  finer 
  and 
  less 
  fossiliferous 
  as 
  the 
  river- 
  

   system 
  reached 
  its 
  base-level. 
  

  

  