﻿262 
  E. 
  RAY 
  LANKESTEll. 
  

  

  Principal 
  families 
  : 
  Nemastoraidae 
  (Nemastoma). 
  

   Trogulidfe 
  (Trogulus). 
  

  

  Tribe 
  /3. 
  Apagosterni. 
  — 
  Metasteruum 
  of 
  prosoma 
  short, 
  

   transverse, 
  not 
  immovably 
  wedged 
  between 
  tlie 
  coxa? 
  ; 
  pro- 
  

   sternum 
  large, 
  quadrate. 
  A 
  distinct 
  maxillary 
  lobe 
  on 
  the 
  

   coxa 
  o£ 
  the 
  fourth 
  appendage. 
  

   Families: 
  Ischyropsalidse 
  (Ischyropsalis). 
  

   Phalangiidse 
  (P 
  h 
  al 
  an 
  g 
  i 
  u 
  m) 
  . 
  

  

  Nearly 
  related 
  to 
  the 
  Opilioues 
  are 
  the 
  genera 
  from 
  the 
  

   Carboniferous 
  strata 
  constituting- 
  the 
  group 
  Anthracomarti. 
  

   These 
  genera, 
  of 
  which 
  the 
  best 
  known 
  are 
  Eophrynus 
  and 
  

   Anthracomartus, 
  seem 
  to 
  have 
  differed 
  from 
  the 
  existing 
  

   Opiliones 
  in 
  retaining 
  a 
  movable 
  joint 
  between 
  the 
  prosoma 
  

   and 
  opisthosoma, 
  and 
  in 
  the 
  presence 
  of 
  movable 
  lateral 
  

   plates 
  upon 
  the 
  terga 
  of 
  the 
  opisthosoma. 
  

  

  Remarks 
  on 
  the 
  Opiliones.— 
  These 
  include 
  the 
  harvest- 
  

   men, 
  sometimes 
  also 
  called 
  Daddy-long-legs, 
  with 
  round 
  un- 
  

   divided 
  bodies 
  and 
  very 
  long, 
  easily 
  detached 
  legs. 
  The 
  

   intromittent 
  organs 
  of 
  the 
  male 
  are 
  remarkable 
  for 
  their 
  

   complexity 
  and 
  elaboration. 
  The 
  confluence 
  of 
  the 
  regions 
  

   of 
  the 
  body 
  and 
  the 
  dislocation 
  of 
  apertures 
  from 
  their 
  

   typical 
  position 
  are 
  results 
  of 
  degeneration. 
  The 
  Opiliones 
  

   seem 
  to 
  lead 
  on 
  from 
  the 
  spiders 
  to 
  the 
  mites. 
  (Reference 
  to 
  

   literature, 
  39.) 
  

  

  Order 
  9. 
  Rhynchostomi 
  = 
  Acari 
  (see 
  Fig. 
  78). 
  — 
  Degenerate 
  

   Arachnids 
  resembling 
  the 
  Opiliones 
  in 
  many 
  structural 
  points, 
  

   but 
  chiefly 
  distinguishable 
  from 
  them 
  by 
  the 
  following 
  

   features 
  : 
  — 
  The 
  basal 
  segments 
  of 
  the 
  appendages 
  of 
  the 
  

   second 
  pair 
  are 
  united 
  in 
  the 
  middle 
  line 
  behind 
  the 
  mouth 
  ; 
  

   those 
  of 
  the 
  third, 
  fourth, 
  fifth, 
  and 
  sixth 
  pairs 
  are 
  widely 
  

   separated 
  and 
  not 
  provided 
  with 
  sterno-coxal 
  (maxillary) 
  

   lobes, 
  and 
  take 
  no 
  share 
  in 
  mastication 
  ; 
  the 
  respiratory 
  

   stigmata, 
  when 
  present, 
  usually 
  belong 
  to 
  the 
  prosoma, 
  and 
  

   the 
  primitive 
  segmentation 
  of 
  the 
  opisthosoma 
  has 
  entirely 
  

   or 
  almost 
  entirely 
  disappeared. 
  

  

  Sub-order 
  a. 
  Notostigmata. 
  — 
  Opisthosoma 
  consisting 
  of 
  

   ten 
  segments 
  defined 
  by 
  integumented 
  grooves, 
  the 
  anterior 
  

  

  