﻿256 
  , 
  E. 
  BAY 
  LANKESTER. 
  

  

  and 
  tlie 
  lamina. 
  Appendages 
  of 
  second 
  pair 
  very 
  large 
  and 
  

   completely 
  chelate, 
  their 
  basal 
  segments 
  meeting 
  in 
  the 
  

   middle 
  line, 
  as 
  in 
  the 
  Uropygi, 
  and 
  provided 
  in 
  front 
  with 
  

   membranous 
  lip-like 
  processes 
  underlying 
  the 
  proboscis. 
  

   Appendages 
  of 
  the 
  third, 
  fourth, 
  fifth, 
  and 
  sixth 
  pairs 
  similar 
  

   in 
  form 
  and 
  function, 
  tipped 
  with 
  two 
  claws, 
  their 
  basal 
  

   segments 
  in 
  contact 
  in 
  the 
  median 
  ventral 
  line. 
  The 
  prse- 
  

   genital 
  somite 
  wide, 
  not 
  constricted, 
  with 
  large 
  tergal 
  plate, 
  

   but 
  with 
  its 
  sternal 
  plate 
  small 
  or 
  inconspicuous. 
  Opistho- 
  

   soma 
  composed, 
  at 
  least 
  in 
  many 
  cases, 
  of 
  eleven 
  somites, 
  

   the 
  eleventh 
  somite 
  very 
  small, 
  often 
  hidden 
  within 
  the 
  

   tenth. 
  Respiratory 
  organs 
  in 
  the 
  form 
  of 
  tracheal 
  tubes 
  

   opening 
  by 
  a 
  pair 
  of 
  stigmata 
  in 
  the 
  second 
  and 
  third 
  somites 
  

   of 
  the 
  opisthosoma. 
  Intromittent 
  organ 
  of 
  male 
  beneath 
  

   sternum 
  of 
  the 
  first 
  somite 
  of 
  the 
  opisthosoma. 
  

  

  Sub-order 
  a. 
  Panctenodactyli. 
  — 
  Dorsal 
  plate 
  of 
  prosoma 
  

   (carapace) 
  narrowed 
  in 
  front; 
  the 
  appendages 
  of 
  the 
  first 
  

   pair 
  small, 
  much 
  narrower, 
  taken 
  together, 
  than 
  the 
  posterior 
  

   border 
  of 
  the 
  carapace. 
  Serrula 
  on 
  movable 
  digit 
  of 
  appen- 
  

   dages 
  of 
  first 
  pair 
  fixed 
  throughout 
  its 
  length, 
  and 
  broader 
  

   at 
  its 
  proximal 
  than 
  at 
  its 
  distal 
  end 
  ; 
  the 
  immovable 
  digit 
  

   with 
  an 
  external 
  process. 
  

  

  Family 
  Cheliferidge 
  (Chelifer 
  (Figs, 
  m, 
  67, 
  68), 
  Chiri- 
  

   dium). 
  

   ,, 
  Garypidffi 
  (Gary 
  pus). 
  

  

  Sub-order 
  h. 
  Hemictenodactyli. 
  — 
  Dorsal 
  plate 
  of 
  prosoma 
  

   scarcely 
  narrowed 
  in 
  front; 
  the 
  appendages 
  of 
  the 
  first 
  pair 
  

   large, 
  not 
  much 
  narrower, 
  taken 
  together, 
  than 
  the 
  posterior 
  

   border 
  of 
  the 
  carapace. 
  The 
  serrula 
  or 
  the 
  movable 
  digit 
  

   free 
  at 
  its 
  distal 
  end, 
  narrowed 
  at 
  the 
  base; 
  no 
  external 
  

   lamina 
  on 
  the 
  immovable 
  digit. 
  

   Family 
  Obisiidte 
  (Obisium, 
  Pseudobisium). 
  

  

  „ 
  Clithoniida3 
  (Clithonius, 
  Tridenchthonius). 
  

  

  Remarks. 
  — 
  The 
  book-scorpions 
  — 
  so 
  called 
  because 
  they 
  

   were, 
  in 
  old 
  times, 
  found 
  not 
  unfrequently 
  in 
  libraries 
  — 
  are 
  

   found 
  in 
  rotten 
  wood 
  and 
  under 
  stones. 
  The 
  similarity 
  of 
  

   the 
  form 
  of 
  their 
  appendages 
  to 
  those 
  of 
  the 
  scorpions 
  

  

  