﻿Geology 
  and 
  Mineralogy 
  . 
  23^ 
  

  

  Pterygotus. 
  The 
  occurrence 
  of 
  Pteraspis 
  and 
  Pterygotus 
  indi- 
  

   cate 
  that 
  the 
  beds 
  at 
  McAra 
  Brook, 
  above 
  and 
  below 
  the 
  post- 
  

   road, 
  are 
  referable 
  to 
  the 
  summit 
  of 
  the 
  Silurian 
  system 
  or 
  the 
  

   lowermost 
  portion 
  of 
  the 
  Devonian." 
  

  

  Mr. 
  Lambe 
  reports 
  the 
  following 
  Cretaceous 
  fossils 
  from 
  Red 
  

   Deer 
  River 
  district 
  of 
  Alberta, 
  viz. 
  : 
  

  

  " 
  Considering 
  first 
  the 
  fossils 
  from 
  the 
  Belly 
  River 
  formation, 
  

   the 
  following 
  provisional 
  enumeration 
  may 
  be 
  made 
  of 
  them 
  : 
  — 
  

  

  1. 
  Chelonia: 
  

  

  Fragments 
  of 
  the 
  dorsal 
  and 
  ventral 
  shield 
  of 
  Plastomenits 
  

   coalescens^ 
  Cope. 
  

  

  2. 
  Crocodilia 
  : 
  

  

  Parts 
  of 
  the 
  rami 
  of 
  mandibles 
  of 
  a 
  species 
  of 
  PottosauruSy 
  

   Agassiz. 
  

  

  3. 
  Dinosauria 
  : 
  

  

  a. 
  Numerous 
  maxillae 
  and 
  rami 
  of 
  mandibles 
  and 
  some 
  of 
  the 
  

   principal 
  bones 
  of 
  Trachodon 
  mirabilis^ 
  Leidy. 
  

  

  b. 
  A 
  maxilla 
  with 
  teeth, 
  a 
  separate 
  tooth 
  and 
  a 
  right 
  ramus 
  

   of 
  a 
  species 
  of 
  Triceratops, 
  3Iarsh. 
  

  

  c. 
  Separate 
  teeth 
  and 
  terminal 
  phalanges 
  of 
  Xce^r/j95 
  incrassa- 
  

   tus, 
  Cope. 
  

  

  d. 
  The 
  upper 
  part 
  of 
  the 
  cranium 
  of 
  a 
  species 
  of 
  Nodosaurus, 
  

   Marsh." 
  w. 
  

  

  2. 
  TJte 
  Hereford 
  Earthqua'ke 
  of 
  December 
  17, 
  1896 
  ; 
  by 
  

   Charles 
  Davisox, 
  Sc.D., 
  F.G.8., 
  303 
  pp. 
  8vo. 
  Birmingham, 
  

   1899 
  (Cornish 
  Brothers). 
  — 
  The 
  careful 
  investigation 
  of 
  the 
  

   phenomena 
  connected 
  with 
  an 
  important 
  earthquake 
  is 
  a 
  labori- 
  

   ous 
  undertaking, 
  but 
  one 
  which 
  is 
  of 
  great 
  value 
  in 
  its 
  bearing 
  

   upon 
  our 
  knowledge 
  of 
  earthquakes 
  in 
  general. 
  In 
  the 
  case 
  of 
  

   the 
  Hereford 
  earthquake 
  of 
  Dec. 
  17, 
  1896, 
  discussed 
  in 
  the 
  

   present 
  volume, 
  Dr. 
  Davison 
  has 
  shown 
  unwearied 
  energy 
  in 
  

   bringing 
  the 
  data 
  together 
  and 
  much 
  judgment 
  and 
  skill 
  in 
  

   drawing 
  conclusions 
  from 
  them. 
  

  

  Of 
  the 
  several 
  regions 
  in 
  Great 
  Britain 
  in 
  w^hich 
  notable 
  earth- 
  

   quakes 
  have 
  taken 
  place, 
  that 
  of 
  the 
  occurrence 
  here 
  described, 
  

   in 
  the 
  southeast 
  of 
  Herefordshire, 
  is 
  especially 
  favorably 
  situated 
  

   for 
  observation 
  both 
  geos^raphically 
  and 
  as 
  regards 
  distribution 
  

   of 
  population. 
  Here 
  occurred 
  also 
  the 
  earthquake 
  of 
  October 
  6, 
  

   1863, 
  investigated 
  by 
  Mr. 
  E. 
  J. 
  Lowe 
  ; 
  while 
  another, 
  less 
  

   violent, 
  occurred 
  in 
  October 
  30, 
  1868. 
  In 
  1896, 
  however, 
  the 
  

   shocks 
  were 
  more 
  immerous 
  and 
  severe, 
  resulting 
  in 
  a 
  very 
  con- 
  

   siderable 
  amount 
  of 
  damage 
  to 
  buildings 
  in 
  the 
  region 
  of 
  greatest 
  

   intensity 
  about 
  Hereford. 
  The 
  effect 
  was 
  distinctly 
  felt 
  even 
  at 
  

   extreme 
  points 
  in 
  the 
  north 
  and 
  south 
  of 
  England 
  and 
  in 
  Ireland. 
  

  

  The 
  record 
  of 
  observations, 
  contained 
  in 
  Part 
  I 
  (pp. 
  10-201) 
  

   of 
  the 
  present 
  volume, 
  includes 
  some 
  2902 
  separate 
  accounts 
  from 
  

   1943 
  places. 
  The 
  discussion 
  of 
  these 
  data 
  has 
  made 
  it 
  possible 
  

   to 
  locate 
  with 
  accuracy 
  the 
  epicentral 
  region 
  with 
  the 
  isoseismal 
  

   lines; 
  also 
  the 
  isacoustic 
  lines, 
  "or 
  lines 
  of 
  equal 
  sound 
  intensity; 
  

   the 
  direction 
  of 
  the 
  shocks 
  at 
  various 
  points 
  w^ith 
  the 
  coseismal 
  

  

  