﻿FOUND 
  ON 
  RATS 
  IN 
  EGYPT. 
  

  

  217 
  

  

  lateral 
  margins. 
  Sterno-ventral 
  plate 
  practically 
  uniform 
  in 
  width 
  posteriorly, 
  the 
  

   sides 
  being 
  almost 
  straight 
  ; 
  it 
  bears 
  ten 
  pairs 
  of 
  hairs 
  and 
  a 
  single 
  unpaired 
  posterior 
  

   hair 
  on 
  its 
  surface. 
  Behind 
  each 
  of 
  the 
  coxae 
  of 
  the 
  last 
  pair 
  of 
  legs 
  there 
  is 
  a 
  pair 
  

   of 
  platelets. 
  Peritreme 
  very 
  long, 
  apparently 
  extending 
  beyond 
  the 
  first 
  coxa. 
  

   Chelicera 
  fairly 
  long 
  ; 
  apparently 
  the 
  digits 
  are 
  fused 
  together 
  and 
  they 
  are 
  accom- 
  

   panied 
  by 
  a 
  free 
  slender 
  process 
  or 
  flagellum, 
  which 
  is 
  as 
  long 
  as 
  the 
  digits 
  themselves 
  

   and 
  furnished 
  with 
  a 
  sharp 
  little 
  tooth. 
  Legs. 
  Anterior 
  surface 
  of 
  coxa 
  of 
  second 
  

   leg 
  armed 
  with 
  a 
  tooth 
  as 
  in 
  the 
  female. 
  Tarsi 
  of 
  third 
  and 
  fourth 
  legs 
  long 
  and 
  

   slender 
  ; 
  there 
  is 
  a 
  little 
  conical 
  protuberance 
  near 
  the 
  middle 
  of 
  the 
  ventral 
  surface 
  

   of 
  the 
  distal 
  part 
  of 
  these 
  tarsi. 
  

   Length 
  of 
  body, 
  "95 
  mm. 
  

  

  Fig. 
  3. 
  Dermanyssus 
  muris, 
  Hirst; 
  ventral 
  view 
  of 
  deutonymph. 
  

  

  Deutonymph* 
  Dorsal 
  shield 
  closely 
  resembling 
  that 
  of 
  the 
  female. 
  On 
  the 
  side 
  

   of 
  the 
  body 
  above 
  the 
  proximal 
  segments 
  of 
  the 
  second 
  leg 
  there 
  is 
  a 
  small 
  but 
  

   distinct 
  oval 
  plate. 
  Sternal 
  plate 
  long 
  ; 
  its 
  posterior 
  end 
  is 
  bluntly 
  pointed 
  and 
  

   projects 
  well 
  beyond 
  the 
  last 
  coxae, 
  four 
  (sometimes 
  five 
  ?) 
  pairs 
  of 
  hairs 
  are 
  present 
  

   on 
  it; 
  on 
  each 
  side 
  of 
  the 
  posterior 
  end 
  of 
  this 
  plate, 
  there 
  are 
  three 
  minute 
  

   platelets, 
  but 
  they 
  are 
  inconspicuous. 
  A 
  distinct 
  bilobed 
  platelet 
  is 
  also 
  present 
  

  

  * 
  The 
  deutonymph 
  described 
  above, 
  and 
  also 
  those 
  of 
  the 
  two 
  other 
  species 
  of 
  

   Dermanyssus 
  described 
  in 
  this 
  report, 
  are 
  probably 
  females. 
  

  

  