﻿STRUCTURE 
  AND 
  CLASSIFICATION 
  OF 
  THE 
  ARACHNIDA. 
  241 
  

  

  united 
  iu 
  the 
  middle 
  line 
  acd 
  incapable 
  of 
  lateral 
  movement; 
  

   appendages 
  of 
  third 
  pair 
  with 
  only 
  the 
  apical 
  segment 
  many- 
  

   joiuted. 
  Opisthosoma 
  without 
  trace 
  of 
  appendages 
  ; 
  its 
  pos- 
  

   terior 
  somites 
  narrowed 
  to 
  form 
  a 
  movable 
  tail 
  for 
  the 
  support 
  

   of 
  the 
  post-anal 
  sclerite, 
  which 
  has 
  no 
  poison 
  glands. 
  

  

  Tribe 
  1. 
  Urotricha. 
  — 
  Dorsal 
  area 
  of 
  prosoma 
  covered 
  with 
  

  

  prcfjen 
  

  

  Fig. 
  54. 
  — 
  Thelyphonus, 
  one 
  of 
  the 
  Pedipalpi. 
  A, 
  ventral 
  view; 
  

   I, 
  chelicera 
  (detached) 
  ; 
  II, 
  clielge; 
  III, 
  palpit'orm 
  limb 
  ; 
  IV 
  to 
  VI, 
  the 
  

   walkini^ 
  legs 
  ; 
  stc, 
  sternn-coxal 
  process 
  (unathobase) 
  of 
  the 
  chelae; 
  st^, 
  

   anterior 
  sternal 
  plate 
  of 
  the 
  prosoma 
  ; 
  st", 
  posterior 
  sternal 
  plate 
  of 
  tlie 
  

   prosoma; 
  pregen, 
  position 
  of 
  the 
  praj-genital 
  somite 
  (not 
  seen); 
  I, 
  I, 
  

   position 
  of 
  the 
  two 
  pulmonary 
  sacs 
  of 
  tlie 
  rii^ht 
  side; 
  1 
  to 
  11, 
  somites 
  

   of 
  the 
  opisthosoma 
  (mesosoina 
  plus 
  metasoma) 
  ; 
  msff, 
  stigmata 
  of 
  the 
  

   tergo-sternal 
  muscles 
  ; 
  an, 
  anus. 
  B, 
  dorsal 
  view 
  of 
  the 
  opisthosoma 
  of 
  

   the 
  same 
  ; 
  pregen, 
  the 
  prse-genital 
  somite 
  ; 
  /;, 
  the 
  tergal 
  stigmata 
  of 
  the 
  

   tergo-sternal 
  muscles; 
  paf, 
  post-anal 
  segmented 
  filament 
  corresponding 
  

   to 
  the 
  post-anal 
  spine 
  of 
  Limulus. 
  (From 
  Laukester, 
  ' 
  Quart. 
  Journ, 
  

   Micr. 
  Sci.,' 
  N.S., 
  vol. 
  xxi, 
  ISSl.) 
  

  

  a 
  single 
  shield 
  (? 
  two 
  in 
  Gleralinura), 
  bearing 
  median 
  and 
  

   lateral 
  eyes. 
  Post-anal 
  sclerite 
  modified 
  as 
  a 
  long, 
  many- 
  

  

  