﻿226 
  STANLEY 
  HIRST. 
  — 
  ON 
  THE 
  PARASITIC 
  ACARI 
  

  

  tubular 
  part 
  of 
  the 
  peritreme 
  appears 
  to 
  vary 
  in 
  length, 
  in 
  mounted 
  preparations 
  of 
  

   this 
  and 
  other 
  Gamasid 
  mites, 
  but 
  I 
  think 
  that 
  this 
  is 
  merely 
  due 
  to 
  the 
  fact 
  that 
  this 
  

   tube 
  can 
  only 
  be 
  readily 
  seen 
  for 
  its 
  full 
  length 
  when 
  filled 
  throughout 
  with 
  air.) 
  

   Length 
  of 
  body 
  (distended 
  specimen), 
  '95 
  mm. 
  

  

  <J. 
  Dorsal 
  shield 
  almost 
  as 
  wide 
  and 
  long 
  as 
  the 
  body, 
  but 
  leaving 
  a 
  narrow 
  lateral 
  

   strip 
  of 
  unprotected 
  integument 
  (except 
  anteriorly) 
  ; 
  hairs 
  on 
  its 
  dorsal 
  surface 
  

   rather 
  long 
  and 
  fine 
  ; 
  a 
  longitudinal 
  series 
  of 
  paired 
  hairs 
  runs 
  down 
  the 
  middle, 
  

   those 
  of 
  the 
  last 
  pair 
  being 
  placed 
  close 
  together 
  at 
  the 
  end 
  ; 
  there 
  are 
  a 
  few 
  other 
  

   symmetrically 
  arranged 
  hairs 
  near 
  the 
  middle 
  and 
  also 
  a 
  lateral 
  series. 
  Sternal 
  plate 
  

  

  "Fig. 
  12. 
  Leiognathus 
  bacoti, 
  Hirst, 
  $; 
  ventral 
  and 
  dorsal 
  aspects. 
  

  

  long, 
  narrow, 
  and 
  furnished 
  with 
  eight 
  or 
  nine 
  pairs 
  of 
  long 
  hairs 
  and 
  the 
  usual 
  un- 
  

   paired 
  posterior 
  hair 
  ; 
  it 
  is 
  slightly 
  narrowed 
  before 
  the 
  anal 
  portion. 
  Peritreme 
  

   extending 
  as 
  far 
  forwards 
  as 
  the 
  anterior 
  surface 
  of 
  the 
  coxa 
  of 
  the 
  second 
  leg 
  or 
  some- 
  

   what 
  further. 
  Fingers 
  of 
  chelicera 
  short 
  and 
  difficult 
  to 
  make 
  out. 
  Length 
  of 
  body, 
  

   •43 
  mm. 
  

  

  Protonymph. 
  Anterior 
  dorsal 
  shield 
  of 
  moderate 
  size 
  and 
  provided 
  with 
  twenty 
  

   hairs 
  (arranged 
  as 
  shown 
  in 
  fig. 
  14), 
  all 
  of 
  them 
  being 
  long, 
  except 
  those 
  of 
  the 
  first 
  

   pair. 
  Posterior 
  dorsal 
  shield 
  situated 
  at 
  the 
  extreme 
  end 
  of 
  the 
  body 
  and 
  furnished 
  

  

  