﻿166 
  

  

  BRUCE 
  F. 
  CUMMINGS. 
  

  

  This 
  second 
  species 
  is 
  probably 
  new, 
  but 
  is 
  represented 
  by 
  only 
  two 
  poor 
  specimens: 
  

   The 
  fact 
  that 
  they 
  stand 
  so 
  near 
  to 
  the 
  species 
  about 
  to 
  be 
  described 
  affords 
  strong 
  

   presumptive 
  evidence 
  that 
  the 
  real 
  host 
  of 
  L. 
  spermophili 
  is 
  Spermophilus 
  (or 
  Citellus) 
  

   and 
  not 
  the 
  Murid 
  Cricetidus. 
  A 
  reference 
  to 
  the 
  published 
  descriptions 
  of 
  species 
  

   from 
  squirrels, 
  e.g., 
  Piaget's 
  Haematopinus 
  setosus 
  from 
  Xerus 
  guttulus 
  and 
  

   Polyplax 
  (?) 
  montana 
  (Osborn) 
  from 
  Sciurus 
  cinereus, 
  makes 
  it 
  probable 
  that 
  at 
  least 
  

   a 
  few 
  of 
  these 
  will 
  be 
  found 
  to 
  fall 
  very 
  naturally 
  into 
  the 
  new 
  genus. 
  

  

  Linognathoides 
  occupies 
  a 
  position 
  midway 
  between 
  the 
  genera 
  Linognaihus 
  and 
  

   Polyplax. 
  The 
  Polyplax 
  characters 
  are 
  the 
  strongly 
  chitinised 
  abdominal 
  pleurites, 
  

   which 
  project 
  on 
  each 
  side 
  from 
  the 
  sides 
  of 
  the 
  abdomen 
  as 
  blunt 
  teeth, 
  and 
  the 
  

   small 
  size 
  of 
  the 
  spiracles. 
  The 
  Linognaihus 
  characters 
  are 
  the 
  large, 
  soft 
  abdomen 
  

   without 
  tergites 
  or 
  sternites, 
  fat 
  and 
  much 
  distended 
  (so 
  that 
  it 
  is 
  difficult 
  to 
  clear 
  

   with 
  potash), 
  and 
  the 
  long 
  hairs 
  which 
  clothe 
  it 
  dorsally 
  and 
  ventrally. 
  Other 
  

   generic 
  characters 
  may 
  be 
  taken 
  from 
  the 
  head, 
  which 
  widens 
  suddenly 
  behind 
  the 
  

   antennae, 
  the 
  sexual 
  dimorphism 
  present 
  in 
  the 
  latter, 
  and 
  the 
  terminal 
  segment 
  

   of 
  the 
  abdomen 
  of 
  the 
  male, 
  which 
  is 
  drawn 
  out 
  on 
  each 
  side 
  (fig. 
  3) 
  into 
  a 
  finger- 
  

   shaped 
  lobe, 
  exactly 
  as 
  in 
  Piaget's 
  figure 
  of 
  H. 
  setosus. 
  

  

  Linognathoides 
  sperm 
  ophili, 
  sp. 
  nov. 
  (fig. 
  3). 
  

  

  External 
  Form, 
  Male. 
  — 
  Head 
  : 
  The 
  first 
  segment 
  of 
  the 
  antennae 
  is 
  the 
  broadest, 
  

   and 
  at 
  its 
  distal 
  end 
  on 
  the 
  upper 
  surface 
  is 
  a 
  minute, 
  short 
  denticle 
  or 
  " 
  thorn." 
  

   There 
  is 
  another 
  denticle 
  at 
  the 
  distal 
  anterior 
  angle 
  of 
  the 
  third 
  segment. 
  The 
  third 
  

   segment 
  differs 
  from 
  that 
  of 
  the 
  female 
  in 
  that 
  the 
  distal 
  anterior 
  angle 
  projects 
  

   somewhat 
  and 
  the 
  anterior 
  lateral 
  margin 
  is 
  consequently 
  longer 
  than 
  the 
  posterior. 
  

   Thorax 
  broadening 
  posteriorly. 
  No 
  sternal 
  plates 
  visible. 
  First 
  pair 
  of 
  legs 
  with 
  

   the 
  claw 
  bifid 
  at 
  the 
  tip 
  ; 
  coxae 
  of 
  all 
  three 
  pairs 
  widely 
  separated, 
  but 
  those 
  of 
  the 
  

   first 
  pair 
  nearer 
  to 
  each 
  other 
  than 
  those 
  of 
  the 
  other 
  two 
  pairs. 
  Abdomen 
  : 
  The 
  

   end 
  of 
  the 
  abdomen 
  is 
  dorsally 
  produced 
  into 
  a 
  rectangular 
  flap 
  (fig. 
  3) 
  formed 
  by 
  the 
  

   tergite 
  of 
  the 
  terminal 
  segment. 
  On 
  each 
  side 
  of 
  this 
  flap 
  the 
  pleurae 
  are 
  produced 
  

   into 
  two 
  finger-shaped 
  processes, 
  one 
  on 
  each 
  side, 
  converging 
  inwards 
  and 
  meeting 
  

   each 
  other 
  at 
  the 
  tip. 
  On 
  the 
  ventral 
  side 
  a 
  membrane 
  stretches 
  across 
  between 
  

   these 
  two 
  processes. 
  From 
  the 
  base 
  of 
  each 
  process 
  a 
  splint-like 
  piece 
  of 
  chitin 
  runs 
  

   forward 
  on 
  the 
  ventral 
  surface 
  to 
  meet 
  the 
  genital 
  plate, 
  which 
  is 
  of 
  the 
  form 
  shewn 
  

   in 
  the 
  figure. 
  

  

  External 
  Form, 
  Female. 
  —Head-: 
  The 
  pre-antennal 
  area 
  is 
  longer 
  than 
  it 
  is 
  in 
  the 
  

   male 
  ; 
  the 
  denticles 
  are 
  absent 
  from 
  the 
  antennae, 
  and 
  the 
  third 
  segment 
  of 
  the 
  latter 
  

   is 
  of 
  the 
  same 
  form 
  as 
  the 
  second. 
  Abdomen 
  as 
  in 
  the 
  male, 
  the 
  sutures 
  between 
  

   the 
  segments 
  are 
  difficult 
  to 
  see, 
  and 
  the 
  tergites 
  and 
  sternites 
  are 
  absent. 
  It 
  is 
  

   rather 
  more 
  swollen, 
  soft 
  and 
  ovate 
  than 
  in 
  the 
  male. 
  The 
  pleurites 
  do 
  not 
  differ 
  

   in 
  shape 
  from 
  those 
  of 
  the 
  male 
  (fig. 
  3). 
  The 
  gonopods 
  are 
  triangular, 
  the 
  apex 
  of 
  

   each 
  triangle 
  pointing 
  inwards. 
  Between 
  the 
  gonopods 
  is 
  a 
  triangular 
  genital 
  plate, 
  

   with 
  the 
  apex 
  pointing 
  backwards. 
  In 
  front 
  of 
  this 
  plate 
  is 
  a 
  second 
  one, 
  transverse 
  

   in 
  position 
  and 
  broader 
  than 
  long. 
  

  

  Chaetotaxy 
  and 
  Colouration, 
  Male.— 
  Head 
  : 
  On 
  the 
  margin 
  of 
  the 
  pre-antennal 
  

   area 
  two 
  small 
  hairs, 
  one 
  on 
  each 
  side 
  of 
  the 
  oral 
  cone. 
  A 
  longer 
  one 
  on 
  each 
  side, 
  

   a 
  little 
  further 
  back 
  ; 
  near 
  the 
  latter, 
  but 
  just 
  inside 
  the 
  margin, 
  another 
  hair. 
  

  

  