﻿344 
  JAMES 
  WATERSTON. 
  

  

  species 
  1 
  have 
  personally 
  examined, 
  this 
  equivalence 
  cannot 
  be 
  maintained. 
  But 
  

   even 
  allowing 
  for 
  this, 
  there 
  is 
  still 
  a 
  discrepancy 
  between 
  the 
  number 
  of 
  joints 
  given 
  

   by 
  Ashmead 
  and 
  Forster 
  respectively. 
  Ashmead 
  was 
  evidently 
  acquainted 
  with 
  

   species, 
  reckoned 
  by 
  him 
  as 
  Pleurotropis, 
  Forst., 
  which 
  possess 
  a 
  four- 
  jointed 
  funicle, 
  

   and 
  Crawford 
  (Bull. 
  U.S. 
  Dept. 
  Agric, 
  Tech. 
  Ser. 
  no. 
  19, 
  pt. 
  ii, 
  1910) 
  suggests 
  that 
  

   one 
  such 
  form, 
  P. 
  atamiemis, 
  Ashmead, 
  is 
  probably 
  an 
  undescribed 
  genus. 
  In 
  the 
  

   paper 
  just 
  quoted 
  Crawford 
  states 
  that 
  in 
  several 
  Japanese 
  species 
  the 
  § 
  § 
  have 
  a 
  

   three-jointed 
  funicle, 
  and 
  presumably 
  the 
  American 
  species 
  to 
  which 
  he 
  has 
  supplied 
  

   a 
  key 
  (Proc. 
  U.S. 
  Nat. 
  Mus., 
  xliii, 
  p. 
  177, 
  1913) 
  answer 
  to 
  this 
  description. 
  In 
  any 
  

   case 
  P. 
  ielenomi, 
  Crawford 
  (Proc. 
  U.S. 
  Nat. 
  Mus., 
  xl., 
  p. 
  445, 
  1911), 
  from 
  Uganda, 
  

   has 
  three 
  funicular 
  joints 
  and 
  otherwise 
  agrees 
  with 
  the 
  sense 
  in 
  which 
  Pleurotropis 
  

   is 
  here 
  employed. 
  

  

  The 
  fore 
  wing 
  of 
  the 
  genus 
  is 
  remarkable 
  for 
  the 
  great 
  development 
  of 
  

   the 
  marginal 
  vein 
  which 
  is 
  sometimes 
  over 
  twice 
  as 
  long 
  as 
  the 
  submarginal. 
  

   The 
  tiny 
  bristles 
  on 
  the 
  clypeus 
  have 
  evidently 
  considerable 
  value 
  for 
  the 
  taxono- 
  

   mist, 
  but 
  they 
  are 
  hard 
  to 
  observe 
  and 
  seldom 
  well 
  preserved. 
  I 
  have 
  discussed 
  them 
  

   only 
  in 
  describing 
  P. 
  neavei, 
  sp. 
  n. 
  Generally 
  the 
  malar 
  space 
  is 
  large 
  and 
  triangular, 
  

   but 
  it 
  may 
  be 
  much 
  reduced. 
  The 
  mouth-parts 
  of 
  Pleurotropis 
  are 
  of 
  great 
  

   importance. 
  While 
  the 
  trophi 
  are 
  of 
  the 
  usual 
  Entedonine 
  type 
  (see 
  under 
  

   P. 
  neavei), 
  the 
  mandibles 
  exhibit 
  much 
  diversity. 
  They 
  may 
  be 
  bidentate, 
  

   with 
  equal 
  or 
  unequal 
  teeth, 
  and 
  more 
  or 
  less 
  deeply 
  cleft. 
  The 
  inner 
  apical 
  

   edge 
  of 
  the 
  inner 
  tooth 
  may 
  be 
  straight, 
  swollen, 
  or 
  minutely 
  serrate. 
  Pro- 
  

   bably 
  the 
  most 
  natural 
  characters 
  for 
  the 
  separation 
  of 
  the 
  genus 
  into 
  species, 
  

   or 
  at 
  any 
  rate, 
  groups 
  of 
  closely 
  allied 
  species, 
  are 
  to 
  be 
  found 
  here. 
  Fundamental 
  

   as 
  these 
  slight 
  differences 
  appear 
  to 
  be, 
  I 
  have 
  not 
  based 
  the 
  following 
  short 
  key 
  on 
  

   mandibular 
  characters, 
  chiefly 
  because 
  material 
  for 
  dissection 
  has 
  not 
  been 
  available 
  

   in 
  the 
  case 
  of 
  all 
  the 
  species 
  

  

  The 
  scutellum 
  and 
  propodaeum 
  also 
  afford 
  most 
  important 
  characters. 
  In 
  the 
  

   former, 
  differences 
  of 
  sculpture 
  and 
  pattern 
  can 
  be 
  easily 
  expressed, 
  but 
  I 
  have 
  

   found 
  it 
  almost 
  impossible 
  to 
  put 
  into 
  words 
  the 
  moulding 
  of 
  the 
  propodaeum. 
  Mr. 
  

   Terzi's 
  skilful 
  drawings 
  give 
  an 
  adequate 
  representation 
  of 
  this 
  region 
  in 
  the 
  species 
  

   now 
  described. 
  In 
  the 
  discussion 
  of 
  various 
  surface 
  levels 
  and 
  light 
  values 
  between 
  

   author 
  and 
  artist 
  recourse 
  to 
  modelling 
  in 
  plasticine 
  has 
  had 
  satisfactory 
  results. 
  

   On 
  the 
  notum 
  of 
  the 
  propodaeum 
  the 
  chief 
  points 
  to 
  be 
  attended 
  to 
  are 
  the 
  curvature 
  

   of 
  the 
  median 
  keels, 
  their 
  distance 
  apart 
  and 
  the 
  nature 
  of 
  the 
  hollows 
  before 
  the 
  

   stalk, 
  e.g., 
  whether 
  single 
  or 
  multiple, 
  shining 
  or 
  dull 
  ; 
  and 
  in 
  the 
  latter 
  case, 
  whether 
  

   smooth 
  or 
  pitted. 
  On 
  the 
  pleura 
  the 
  position 
  and 
  size 
  of 
  the 
  stigma 
  are 
  of 
  value. 
  

  

  The 
  chief 
  variation 
  of 
  the 
  propodaeum 
  in 
  any 
  species 
  seems 
  to 
  occur 
  inside 
  the 
  

   central 
  keels, 
  where 
  false 
  or 
  incomplete 
  keels 
  are 
  frequently 
  thrown 
  up. 
  The 
  distal 
  

   hollows 
  are 
  much 
  more 
  constant. 
  

  

  In 
  the 
  case 
  of 
  the 
  wings, 
  antennae, 
  and 
  leg 
  joints, 
  the 
  measurements 
  have 
  been 
  

   taken 
  from 
  balsam 
  mounts. 
  Those 
  of 
  the 
  visible 
  segments 
  of 
  the 
  abdomen, 
  the 
  

   total 
  length 
  of 
  each 
  species, 
  and 
  its 
  alar 
  expanse 
  are 
  more 
  approximate, 
  being 
  taken 
  

   from 
  card-mounted 
  specimens, 
  by 
  slipping 
  a 
  micrometer 
  on 
  to 
  the 
  diaphragm 
  of 
  

   the 
  eyepiece 
  (no. 
  iii., 
  with 
  objective 
  a 
  3 
  ) 
  of 
  a 
  binocular 
  dissecting 
  microscope. 
  For 
  

   detailed 
  descriptions, 
  the 
  same 
  objective, 
  with 
  eyepiece 
  no. 
  v. 
  has 
  been 
  used. 
  The 
  

  

  