﻿ll 
  

  

  E. 
  BAY 
  LANKESTER. 
  

  

  cases 
  (see 
  Figs. 
  45 
  and 
  63). 
  The 
  evidence 
  of 
  the 
  exact 
  

   equivalence 
  of 
  the 
  segmentation 
  and 
  appendages 
  of 
  Limulus 
  

   and 
  Scorpio, 
  and 
  of 
  a 
  number 
  of 
  remarkable 
  points 
  of 
  agree- 
  

   ment 
  in 
  their 
  structure, 
  was 
  furnished 
  by 
  Lankester 
  in 
  an 
  

   article 
  published 
  in 
  1881 
  ("Limulus 
  an 
  Arachnid," 
  'Quart. 
  

   Journ. 
  Micr. 
  Sci./ 
  vol. 
  xxi, 
  JST.S.), 
  and 
  in 
  a 
  series 
  of 
  subse- 
  

   quent 
  memoirs, 
  in 
  which 
  the 
  structure 
  of 
  the 
  entosternum, 
  of 
  

   the 
  coxal 
  glands, 
  of 
  the 
  eyes, 
  of 
  the 
  veno-pericardiac 
  muscles. 
  

  

  EiG. 
  5. 
  

  

  Fig. 
  6. 
  

  

  Fig. 
  5. 
  — 
  Entosternum 
  of 
  one 
  of 
  the 
  mygaloniorphous 
  spiders; 
  

   ventral 
  surface. 
  Ph.N., 
  pharyngeal 
  notcli. 
  The 
  three 
  pairs 
  of 
  rod- 
  

   like 
  tendons 
  correspond 
  to 
  the 
  two 
  similar 
  pairs 
  in 
  Limulus, 
  and 
  

   the 
  posterior 
  median 
  process 
  with 
  its 
  repetition 
  of 
  triangular 
  seg- 
  

   ments 
  closely 
  resembles 
  the 
  same 
  process 
  in 
  Limulus. 
  Magnified 
  

   five 
  times 
  linear. 
  (From 
  Lankester, 
  loc. 
  cit.) 
  

  

  Fig. 
  6. 
  — 
  Dorsal 
  surface 
  of 
  the 
  same 
  entosternum 
  as 
  that 
  drawn 
  in 
  

   Fig. 
  5. 
  Ph.N., 
  pharyngeal 
  notch. 
  (After 
  Lankester, 
  loc. 
  cit.) 
  

  

  of 
  the 
  respiratory 
  lamella, 
  and 
  of 
  other 
  parts, 
  was 
  for 
  the 
  

   first 
  time 
  described, 
  and 
  in 
  which 
  the 
  new 
  facts 
  discovered 
  

   were 
  shown 
  uniformly 
  to 
  support 
  the 
  hypothesis 
  that 
  Limulus 
  

   is 
  an 
  Arachnid. 
  A 
  list 
  of 
  these 
  memoirs 
  is 
  given 
  at 
  the 
  close 
  

   of 
  this 
  article 
  (2, 
  3, 
  4, 
  5, 
  and 
  13). 
  The 
  Eurypterines 
  (Grigan- 
  

   tostraca) 
  were 
  included 
  in 
  the 
  identification, 
  although 
  at 
  

   that 
  time 
  they 
  were 
  supposed 
  to 
  possess 
  only 
  five 
  pairs 
  of 
  

   anterior 
  or 
  prosomatic 
  appendages. 
  They 
  have 
  now 
  been 
  

   shown 
  to 
  possess 
  six 
  pairs 
  (Fig. 
  47), 
  as 
  do 
  Limulus 
  and 
  

   Scorpio. 
  

  

  The 
  various 
  comparisons 
  previously 
  made 
  between 
  the 
  

  

  