﻿234 
  E. 
  HAY 
  LANKBSTER. 
  

  

  the 
  basal 
  segments 
  of 
  the 
  fifth 
  and 
  sixth 
  pairs 
  of 
  appendages. 
  

   Appendages 
  of 
  first 
  pair 
  tri-segmented, 
  chelate 
  ; 
  of 
  second 
  

   pair 
  chelate, 
  with 
  their 
  basal 
  segments 
  subserving 
  mastica- 
  

   tion 
  ; 
  of 
  third, 
  fourth, 
  fifth, 
  and 
  sixth 
  pairs 
  similar 
  in 
  form 
  

   and 
  function, 
  except 
  that 
  in 
  recenb 
  and 
  Carboniferous 
  forms 
  

   the 
  basal 
  segments 
  of 
  the 
  third 
  and 
  fourth 
  are 
  provided 
  with 
  

   sterno-coxal 
  (maxillary) 
  lobes, 
  those 
  of 
  the 
  fourth 
  pair 
  meet- 
  

   ing 
  in 
  the 
  middle 
  line 
  and 
  underlying 
  the 
  mouth. 
  The 
  five 
  

   posterior 
  somites 
  of 
  the 
  metasoma 
  constricted 
  to 
  form 
  a 
  

   " 
  tail," 
  the 
  post-anal 
  sclerite 
  persisting 
  as 
  a 
  weapon 
  of 
  offence, 
  

   and 
  provided 
  with 
  a 
  pair 
  of 
  poison 
  glands 
  (see 
  Figs. 
  8, 
  10, 
  12, 
  

   13, 
  14, 
  15, 
  21, 
  22). 
  

  

  Sub-order 
  Apoxypoda. 
  — 
  The 
  third, 
  fourth, 
  fifth, 
  and 
  sixth 
  

   pairs 
  of 
  appendages 
  short, 
  stout, 
  tapering, 
  the 
  segments 
  

   about 
  as 
  wide 
  as 
  long, 
  except 
  the 
  apical^ 
  which 
  is 
  distally 
  

   slender, 
  pointed, 
  slightly 
  curved, 
  and 
  without 
  distinct 
  movable 
  

   claws. 
  

  

  Family 
  Pala3ophonida3, 
  Palasophonus 
  (Figs. 
  48 
  and 
  49). 
  

   Sub-order 
  Dionychopoda. 
  — 
  The 
  third, 
  fourth, 
  fifth, 
  and 
  

   sixth 
  pairs 
  of 
  appendages 
  slender, 
  not 
  evenly 
  tapering, 
  the 
  

   segments 
  longer 
  than 
  wide 
  ; 
  the 
  apical 
  segment 
  short, 
  distally 
  

   truncate, 
  and 
  provided 
  with 
  a 
  pair 
  of 
  movable 
  claws. 
  Basal 
  

   segments 
  of 
  the 
  fifth 
  and 
  sixth 
  pairs 
  of 
  appendages 
  abutting 
  

   against 
  the 
  sternum 
  of 
  the 
  prosoma 
  (see 
  Fig. 
  10 
  and 
  Figs. 
  51, 
  

   52, 
  and 
  53). 
  

  

  Family 
  — 
  Pandinidee 
  (Pan 
  din 
  us, 
  Opisthophthalmus, 
  

   Urodacus). 
  

   „ 
  V£ejovida3 
  (Vasjovis, 
  lurus, 
  Euscorpius, 
  

  

  B 
  r 
  o 
  t 
  e 
  a 
  s) 
  . 
  

   ,, 
  Bothi*iurida3 
  (Bothriurus, 
  Cercoplionius). 
  

   „ 
  ButhidiB 
  (Buthus, 
  Centrurus). 
  

   „ 
  *Cyclophthalmid£e 
  (Cycloph-' 
  

  

  t 
  halm 
  us) 
  

  

  „ 
  ■^Eoscorpiida) 
  (Eoscorpius, 
  

  

  Centromachus) 
  

  

  Remarks 
  on 
  the 
  Order 
  Scorpionidea. 
  — 
  The 
  scorpion 
  

  

  is 
  one 
  of 
  the 
  great 
  animals 
  of 
  ancient 
  lore 
  and 
  tradition. 
  It 
  

  

  -Carboniferous. 
  

  

  