﻿PROCEEDINGS 
  OF 
  THE 
  UNITED 
  STATES 
  NATIONAL 
  MUSEUM 
  

  

  Issued 
  BMrlrvA- 
  ScjSB 
  ^y 
  '^* 
  

  

  SMITHSONIAN 
  INSTITUTION 
  

  

  U. 
  S. 
  NATIONAL 
  MUSEUM 
  

  

  Vol.103 
  Washington: 
  1953 
  No. 
  331 
  1 
  

  

  TWO 
  NEW 
  NAUCORID 
  BUGS 
  OF 
  THE 
  GENUS 
  AMBRYSUS 
  

  

  By 
  Ira 
  La 
  Rivers^ 
  

  

  The 
  following 
  new 
  Ambrysi 
  were 
  discovered 
  after 
  the 
  manuscripts 
  

   dealing 
  with 
  United 
  States 
  and 
  Mexican 
  species 
  had 
  been 
  completed, 
  

   and 
  this 
  paper 
  is 
  offered 
  as 
  a 
  supplement 
  to 
  these 
  treatments. 
  Keys 
  

   are 
  included 
  to 
  allow 
  the 
  incorporation 
  of 
  the 
  new 
  species 
  into 
  the 
  

   overall 
  keys 
  for 
  the 
  two 
  regions. 
  

  

  Family 
  Naucoridae 
  

  

  Genus 
  Ambrysus 
  Stdl, 
  1862 
  

  

  Ambrysus 
  thertnarum, 
  new 
  species 
  

  

  Figure 
  1, 
  &, 
  c 
  

  

  Description. 
  — 
  A 
  small, 
  pale 
  species, 
  nearly 
  approaching 
  Airibrysus 
  

   fwnebris 
  La 
  Rivers, 
  1949, 
  as 
  the 
  smallest 
  species 
  in 
  the 
  genus, 
  and 
  

   greatly 
  resembling 
  the 
  latter 
  in 
  general 
  conspectus; 
  size 
  7.0-8.0 
  mm. 
  

   long 
  and 
  4.5-5.0 
  mm. 
  wide. 
  Dorsum 
  bicolored, 
  the 
  scutellum 
  and 
  an- 
  

   terior 
  portion 
  yellowish, 
  the 
  posterior 
  area 
  (hemelytra) 
  brownish. 
  

   Venter 
  brownish, 
  contrasting 
  strongly 
  with 
  the 
  yellow-white 
  ap- 
  

   pendages. 
  

  

  Head 
  glistening, 
  yellow, 
  slightly 
  roughened 
  and 
  weakly 
  punctate, 
  

   protuberant 
  before 
  eyes 
  and 
  with 
  the 
  faintest 
  suggestion 
  of 
  trunca- 
  

   tion 
  in 
  front. 
  Eyes 
  blackish, 
  slightly 
  raised 
  above 
  general 
  head 
  sur- 
  

  

  * 
  Department 
  of 
  Biology, 
  University 
  of 
  Nevada, 
  Reno, 
  Nev. 
  

  

  228422—52 
  1 
  

  

  