﻿STRUOTOKE 
  AND 
  CLASSIFICATION 
  OF 
  THE 
  AliACHNlDA. 
  171 
  

  

  Fig. 
  10. 
  

  

  sternal 
  plates 
  of 
  Limulus^ 
  called 
  " 
  cliilaria 
  " 
  by 
  Owen, 
  with 
  

   a 
  pair 
  of 
  appendages 
  (7). 
  Once 
  the 
  identity 
  of 
  the 
  chilaria 
  

  

  with 
  the 
  pentagonal 
  sternal 
  

   plate 
  of 
  the 
  scorpion 
  is 
  

   recognised 
  — 
  an 
  identifica- 
  

   tion 
  first 
  insisted 
  on 
  by 
  Lan- 
  

   kester 
  — 
  the 
  whole 
  series 
  of 
  

   segments 
  and 
  appendages 
  in 
  

   the 
  two 
  animals, 
  Limulns 
  and 
  

   Scorpio, 
  are 
  seen 
  to 
  corres- 
  

   pond 
  most 
  closely, 
  segment 
  

   for 
  segment, 
  with 
  one 
  an- 
  

   other 
  (see 
  Figs, 
  7 
  and 
  8). 
  

  

  Fig. 
  11. 
  

  

  Xtti/y 
  

  

  Fig. 
  10. 
  — 
  Ventral 
  view 
  of 
  a 
  Scorpion, 
  Palamnseus 
  Indus, 
  De 
  

   Gear, 
  to 
  show 
  the 
  arrangement 
  of 
  tlie 
  coxae 
  of 
  the 
  limbs, 
  the 
  sternal 
  

   elements, 
  genital 
  plate 
  and 
  i)cctens. 
  M, 
  mouth 
  beiiiud 
  the 
  oval 
  

   median 
  camerostome 
  ; 
  I, 
  the 
  chelicera;; 
  II, 
  the 
  chelae 
  ; 
  III 
  to 
  VJ, 
  

   the 
  four 
  pairs 
  of 
  walking 
  legs 
  ; 
  VII^o, 
  the 
  genital 
  somite 
  or 
  first 
  

   somite 
  of 
  the 
  mesosoma 
  with 
  the 
  genital 
  operculum 
  (a 
  fused 
  

   pair 
  of 
  limbs); 
  VIII/;, 
  the 
  pectiniferous 
  somite; 
  VLstg 
  to 
  y^llslf/, 
  

   the 
  four 
  pulmonary 
  somites 
  ; 
  met, 
  the 
  pentagonal 
  metasternite 
  of 
  

   the 
  prosoraa 
  behind 
  all 
  the 
  coxae 
  ; 
  x, 
  the 
  sternum 
  of 
  the 
  pectinifer- 
  

   ous 
  somite 
  ; 
  y, 
  the 
  broad 
  first 
  somite 
  of 
  the 
  metasoma. 
  

  

  Fig. 
  11. 
  — 
  Third 
  leg 
  of 
  Liniulus 
  polyphemus, 
  showing 
  the 
  

   division 
  of 
  the 
  fourth 
  segment 
  of 
  the 
  leg 
  by 
  a 
  groove 
  S 
  into 
  two, 
  

   thus 
  giving 
  seven 
  segments 
  to 
  (he 
  leg 
  as 
  in 
  Scorpion. 
  (From 
  a 
  

   drawing 
  by 
  Mr. 
  Pocock.) 
  

  

  The 
  structure 
  of 
  the 
  prosomatic 
  appendages 
  or 
  legs 
  is 
  also 
  

   seen 
  to 
  present 
  many 
  significant 
  points 
  of 
  agreement 
  (see 
  

  

  