﻿326 
  JAMES 
  WATERSTON. 
  

  

  Genus 
  Trigonogastra, 
  Ashmead. 
  

   The 
  two 
  Sphegigasterines 
  described 
  below 
  agree 
  in 
  having 
  the 
  petiole 
  longer 
  than 
  

   the 
  coxae, 
  distinctly 
  in 
  the 
  females 
  and 
  slightly 
  in 
  the 
  males, 
  the 
  parapsidal 
  furrows 
  

   incomplete, 
  no 
  apical 
  cross 
  furrow 
  on 
  the 
  scutellum 
  and 
  the 
  long 
  propodaeum 
  

   punctate. 
  In 
  all 
  the 
  pronotum 
  is 
  truncate 
  and 
  the 
  upper 
  edge 
  acute. 
  Ashmead, 
  

   in 
  diagnosing 
  the 
  genus 
  (Mem. 
  Cam. 
  Mus., 
  i, 
  no. 
  4, 
  pp. 
  330-332, 
  1904), 
  gives 
  as 
  

   type 
  T. 
  aurata, 
  a 
  species 
  I 
  have 
  been 
  unable 
  to 
  trace. 
  T. 
  rugosa, 
  sp. 
  n., 
  and 
  

   T. 
  megacephalus, 
  sp. 
  n., 
  may 
  be 
  separated 
  at 
  once 
  by 
  the 
  antennae. 
  The 
  former 
  

   is 
  a 
  green, 
  the 
  latter 
  a 
  dull 
  purplish 
  black 
  species. 
  

  

  Trigonogasira 
  rugosa, 
  sp. 
  nov. 
  (fig. 
  1). 
  

  

  A 
  moderately 
  and 
  evenly 
  shagreened 
  or 
  reticulate 
  species, 
  with 
  the 
  head, 
  thorax 
  

   and 
  propodaeum 
  very 
  dark 
  green 
  ; 
  the 
  abdomen 
  shining 
  blackish, 
  with 
  a 
  paler 
  brown 
  

   median 
  area 
  (in 
  the 
  £ 
  only) 
  on 
  the 
  first 
  and 
  second 
  segments 
  ; 
  legs 
  brownish 
  yellow 
  

   with 
  darker 
  tarsi 
  ; 
  antennae 
  with 
  the 
  scape 
  lighter, 
  remaining 
  joints 
  darker 
  brown. 
  

  

  <$. 
  — 
  Head 
  large, 
  seen 
  from 
  in 
  front, 
  rounded 
  at 
  the 
  sides, 
  broader 
  than 
  deep, 
  though 
  

   descending 
  with 
  a 
  large 
  malar 
  space 
  to 
  the 
  mouth 
  edge. 
  Vertex 
  so 
  wide 
  as 
  to 
  equal 
  

   the 
  thorax 
  on 
  the 
  intraorbital 
  diameter 
  alone 
  ; 
  ocellar 
  triangle 
  distinctly 
  elevated, 
  

   occupying 
  a 
  little 
  over 
  the 
  central 
  third 
  of 
  the 
  vertex 
  ; 
  no 
  occipital 
  ridge, 
  the 
  vertex 
  

   and 
  occiput 
  merging 
  roundly 
  into 
  one 
  another. 
  Frons 
  concave, 
  dull, 
  gleaming, 
  

   with 
  rather 
  fine 
  reticulation 
  as 
  on 
  the 
  vertex 
  ; 
  scrobes 
  oval, 
  antennae 
  set 
  on 
  the 
  mid 
  

   diameter 
  between 
  the 
  eyes, 
  and 
  well 
  above 
  the 
  middle 
  of 
  the 
  frons 
  ; 
  the 
  mid 
  point 
  of 
  

   the 
  scape 
  is 
  at 
  or 
  above 
  the 
  ocelli. 
  Clypeal 
  edge 
  with, 
  two 
  slight 
  rounded 
  lobes. 
  

  

  Antennae 
  (fig. 
  1, 
  a) 
  long 
  and 
  filiform 
  and 
  of 
  practically 
  the 
  same 
  breadth 
  throughout, 
  

   the 
  club 
  being 
  little 
  expanded. 
  Thirteen 
  joints 
  : 
  scape, 
  pedicel, 
  two 
  ring 
  joints, 
  

   seven 
  funicular, 
  and 
  club 
  of 
  two. 
  Scape 
  as 
  long 
  as 
  the 
  pedicel, 
  the 
  ring 
  joints, 
  the 
  first 
  

   funicular 
  and 
  half 
  of 
  the 
  second, 
  together 
  ; 
  flavescent 
  brown 
  in 
  colour, 
  with 
  about 
  

   half-a-dozen 
  short 
  bristles 
  along 
  the 
  dorsal 
  edge.and 
  one 
  or 
  two 
  ventrally, 
  otherwise 
  

   bare, 
  broadest 
  before 
  the 
  apex, 
  the 
  breadth 
  about 
  one-sixth 
  of 
  the 
  length 
  of 
  the 
  scape. 
  

   Ring 
  joints 
  distinct 
  and 
  separate, 
  the 
  second 
  robust, 
  darker, 
  and 
  half 
  as 
  long 
  again 
  

   as 
  the 
  first. 
  Funicle 
  and 
  club 
  blackish 
  brown 
  ; 
  the 
  funicular 
  joints 
  decreasing 
  in 
  

   length 
  towards 
  the 
  club 
  ; 
  the 
  first 
  is 
  longest, 
  slightly 
  exceeding 
  the 
  second, 
  which 
  

   equals 
  the 
  third, 
  the 
  fifth 
  and 
  sixth 
  again 
  being 
  equal 
  ; 
  the 
  seventh 
  (eleventh) 
  is 
  the 
  

   shortest 
  of 
  all, 
  being 
  to 
  the 
  first 
  in 
  the 
  ratio 
  of 
  five 
  to 
  seven 
  ; 
  the 
  club 
  joints 
  are 
  equal. 
  

   The 
  funicle 
  and 
  club 
  bear 
  elongated 
  " 
  sensoria 
  " 
  with 
  low 
  flanges, 
  and 
  each 
  joint 
  

   shows 
  besides 
  up 
  to 
  fifty 
  or 
  more 
  longish 
  hairs, 
  giving 
  the 
  whole 
  antenna 
  a 
  pilose 
  

   appearance. 
  Length 
  of 
  antenna, 
  1*5 
  mm. 
  

  

  Mandibles 
  (fig. 
  1, 
  c) 
  heterodont, 
  the 
  right 
  with 
  four 
  teeth, 
  of 
  which 
  the 
  outermost 
  

   is 
  the 
  most 
  acute 
  and 
  longest, 
  the 
  second 
  smaller, 
  and 
  the 
  third 
  and 
  fourth 
  equal 
  ; 
  

   left 
  with 
  three 
  equal 
  teeth, 
  the 
  outermost 
  more 
  acute. 
  

  

  Thorax 
  with 
  incomplete 
  parapsidal 
  furrows, 
  and 
  evenly 
  reticulate, 
  of 
  about 
  the 
  

   same 
  coarseness 
  as 
  the 
  head, 
  slightly 
  coarser 
  on 
  scutellum. 
  Propodaeum 
  as 
  long 
  

   as 
  the 
  scutellum, 
  and 
  with 
  only 
  slightly 
  finer 
  reticulation, 
  transverse, 
  with 
  posteriorly 
  

   convergent 
  sides 
  ; 
  produced 
  behind 
  broadly 
  into 
  a 
  neck, 
  so 
  that 
  the 
  whole 
  segment 
  

   from 
  above 
  is 
  roughly 
  a 
  truncate 
  triangle. 
  There 
  is 
  an 
  indefinite 
  median 
  ridge 
  

   and 
  a 
  rather 
  extensive 
  sulcus 
  anteriorly 
  on 
  each 
  side 
  behind 
  the 
  metathoracic 
  edge. 
  

   Spiracles 
  small, 
  oval. 
  

  

  