﻿4 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  loe 
  

  

  The 
  following 
  modification 
  of 
  my 
  key 
  to 
  United 
  States 
  Ambrysi 
  

   (La 
  Rivers, 
  1951) 
  will 
  satisfactorily 
  compare 
  A. 
  thermanmi 
  with 
  its 
  

   closest 
  relatives 
  : 
  

  

  8 
  (7). 
  Female 
  subgenital 
  plate 
  simply, 
  broadly, 
  and 
  smoothly 
  concave 
  apically, 
  

   the 
  lateral 
  bordering 
  angles 
  sharp; 
  concavity, 
  measured 
  in 
  terms 
  of 
  

   depth 
  of 
  concavity 
  against 
  length 
  between 
  bordering 
  lateral 
  angles, 
  never 
  

   less 
  than 
  20 
  percent 
  ; 
  in 
  clean 
  material 
  embolium 
  nearly 
  unicolorous, 
  only 
  

   very 
  faintly 
  lighter 
  exteriorly, 
  no 
  contrasting 
  colors 
  present. 
  

  

  buenoi 
  Usinger, 
  1946 
  

  

  Female 
  subgenital 
  plate, 
  if 
  simply 
  concave, 
  has 
  (a) 
  rounded 
  lateral 
  angles, 
  

  

  or 
  (b) 
  if 
  lateral 
  angles 
  are 
  sharp, 
  then 
  depth 
  of 
  concavity 
  is 
  considerably 
  

  

  less 
  than 
  20 
  percent; 
  in 
  clean 
  material 
  embolium 
  always 
  sharply 
  and 
  

  

  contrastingly 
  transversely 
  bicolored, 
  anterior 
  two-thirds 
  light 
  yellow, 
  

  

  posterior 
  one-third 
  blackish-brown 
  8A 
  

  

  8A 
  (8). 
  Male 
  genital 
  process 
  narrowing 
  to 
  apex, 
  strongly, 
  abruptly 
  and 
  almost 
  

   right-angularly 
  turned 
  outward, 
  giving 
  the 
  appearance 
  of 
  a 
  long, 
  

   attenuated 
  foot 
  with 
  a 
  rather 
  sharp 
  heel 
  ; 
  female 
  subgenital 
  plate 
  

   simply 
  concave 
  at 
  apex, 
  somewhat 
  angularly 
  so. 
  

  

  thermarum, 
  new 
  species 
  

  

  Male 
  genital 
  process 
  not 
  definitely 
  narrowing 
  to 
  apex, 
  and 
  not 
  foot- 
  or 
  

  

  boot-shaped, 
  although 
  curving 
  variably 
  outward 
  ; 
  female 
  subgenital 
  

  

  plate 
  simply 
  and 
  roundly 
  concave 
  at 
  apex__ 
  mormon 
  Montandon, 
  1909 
  

  

  Ambrysus 
  bispinus, 
  new 
  species 
  

  

  Figure 
  1, 
  a, 
  d 
  

  

  Description. 
  — 
  A 
  large, 
  darkly 
  mottled 
  species, 
  well 
  rounded 
  and 
  con- 
  

   vex; 
  size 
  12.0-14.0 
  mm. 
  long 
  and 
  7.0-9.0 
  mm. 
  wide. 
  Dorsum 
  not 
  

   distinctly 
  bicolored 
  (i. 
  e., 
  anterior 
  portion 
  lighter 
  than 
  posterior 
  area) 
  , 
  

   more 
  or 
  less 
  uniformly 
  mottled. 
  Venter 
  yellow 
  or 
  brownish, 
  uni- 
  

   colorous 
  and 
  lighter 
  than 
  dorsum. 
  

  

  Head 
  glistening, 
  yellow-brown, 
  smooth, 
  weakly 
  and 
  vaguely 
  punc- 
  

   tate, 
  slightly 
  and 
  broadly 
  protuberant, 
  and 
  truncate 
  before 
  the 
  eyes. 
  

   Eyes 
  blackish, 
  nearly 
  flush 
  with 
  plane 
  surface 
  of 
  head 
  when 
  viewed 
  

   posteriorly. 
  Head 
  ratios 
  are 
  : 
  Total 
  length 
  to 
  width 
  (including 
  eyes) 
  

   34:54 
  (63 
  percent) 
  ; 
  anterior 
  distance 
  between 
  eyes 
  to 
  posterior 
  dis- 
  

   tance 
  26 
  : 
  33 
  (79 
  percent) 
  ; 
  anterior 
  distance 
  between 
  eyes 
  to 
  inner 
  eye- 
  

   margin 
  26 
  : 
  25 
  ; 
  posterior 
  distance 
  between 
  eyes 
  to 
  greatest 
  length 
  of 
  

   head 
  posterior 
  to 
  this 
  line, 
  33 
  : 
  8 
  (22 
  percent) 
  . 
  

  

  Pronotum 
  glistening, 
  yellowish 
  with 
  brown 
  mottling, 
  sparsely 
  

   punctulate, 
  rugulose 
  behind 
  head; 
  lateral 
  edges 
  smooth, 
  nonserrate, 
  

   rounded, 
  on 
  one 
  specimen 
  with 
  traces 
  of 
  faint 
  pilosity 
  which 
  appears 
  

   to 
  have 
  been 
  rubbed 
  off. 
  Curvature 
  10 
  percent 
  (average 
  52:5); 
  

   posterolateral 
  angles 
  well 
  rounded. 
  Dorsal 
  ratios 
  are: 
  Width 
  be- 
  

   tween 
  anterior 
  angles 
  to 
  greatest 
  pronotal 
  width 
  53 
  : 
  73 
  (73 
  percent) 
  ; 
  

   median 
  length 
  to 
  greatest 
  width 
  39 
  : 
  73 
  (53 
  percent) 
  ; 
  width 
  between 
  

   anterior 
  angles 
  to 
  distance 
  between 
  anterior 
  angle 
  and 
  posterior 
  base- 
  

   line 
  of 
  pronotum 
  63 
  : 
  52. 
  

  

  