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  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.98 
  

  

  Genus 
  AMYDROGMUS 
  Pierce 
  

  

  Amydrogmus 
  Pierce, 
  1913, 
  p. 
  374. 
  (Genotype, 
  A. 
  variabilis 
  Pierce, 
  monobasic 
  

   and 
  original 
  designation.) 
  

  

  This 
  genus 
  is 
  defined 
  by 
  Pierce 
  as 
  follows 
  : 
  

  

  Rostrum 
  with 
  aerobes 
  deep 
  and 
  definite, 
  passing 
  rapidly 
  inferior; 
  rostral 
  striae 
  

   almost 
  obsolete, 
  indicated 
  by 
  faint 
  depressions; 
  third 
  tarsal 
  joint 
  broadly 
  bilobed, 
  

   and 
  pubescent 
  beneath; 
  second 
  abdominal 
  segment 
  subequal 
  to 
  the 
  two 
  following; 
  

   prothorax 
  not 
  tuberculate 
  at 
  sides. 
  

  

  In 
  view 
  of 
  the 
  great 
  variation 
  in 
  depth 
  of 
  the 
  rostral 
  sulci 
  in 
  the 
  

   other 
  genera 
  of 
  the 
  Ophryastini, 
  it 
  seems 
  to 
  me 
  that 
  the 
  most 
  striking 
  

   character 
  of 
  this 
  genus 
  is 
  the 
  thorax, 
  wliich 
  is 
  wider 
  at 
  the 
  apex 
  than 
  

   at 
  the 
  base, 
  a 
  feature 
  that 
  is 
  more 
  differentiating 
  than 
  the 
  nearly 
  

   obsolete 
  rostral 
  striae, 
  and 
  that 
  is 
  sufficient 
  to 
  distinguish 
  Amydrogmus 
  

   from 
  other 
  genera 
  of 
  the 
  group. 
  

  

  AMYDROGMUS 
  VARIABIUS 
  Pierce 
  

  

  Figure 
  63 
  

  

  Amydrogmus 
  variabilis 
  Pierce, 
  1913, 
  p. 
  374. 
  

  

  Pierce's 
  original 
  description 
  is 
  as 
  follows: 
  

  

  Small, 
  resembling 
  Sapotes 
  punciicollis 
  in 
  form, 
  with 
  elytra 
  more 
  or 
  less 
  robust, 
  

   closely 
  covered 
  with 
  pavement 
  scales, 
  which 
  are 
  generally 
  white, 
  but 
  sometimes 
  

   heavily 
  mottled 
  with 
  brown, 
  and 
  with 
  two 
  brown 
  fasciae 
  [stripes] 
  on 
  prothorax. 
  

   Length 
  4-6 
  mm.; 
  width 
  1.75-2.75 
  mm. 
  Beak 
  strongly 
  constricted 
  at 
  base 
  above 
  

   and 
  beneath, 
  a 
  little 
  longer 
  than 
  head 
  above, 
  densely 
  covered 
  with 
  white 
  polygon- 
  

   ally 
  crowded 
  pavement 
  scales, 
  with 
  short 
  erect 
  setae 
  interspersed, 
  apically 
  emargi- 
  

   nate 
  and 
  medially 
  shallowly 
  sulcate, 
  also 
  with 
  feeble 
  longitudinal 
  impressions 
  in 
  

   front 
  of 
  eyes. 
  Antennae 
  densely 
  clothed 
  with 
  scales, 
  with 
  exception 
  of 
  the 
  club, 
  

   which 
  is 
  finely 
  pubescent. 
  Prothorax 
  a 
  little 
  shorter 
  than 
  head; 
  truncate 
  at 
  base 
  

   and 
  apex; 
  ocular 
  lobes 
  small, 
  finely 
  fimbriate; 
  sides 
  broadly 
  arcuate, 
  base 
  not 
  as 
  

   wide 
  as 
  apex, 
  slightly 
  constricted 
  in 
  front 
  of 
  base; 
  surface 
  very 
  unevenly 
  punctate, 
  

   with 
  deep 
  punctures 
  of 
  variable 
  sizes; 
  in 
  specimens 
  showing 
  color, 
  two 
  fasciae 
  

   [stripes] 
  of 
  brown 
  scales; 
  vestiture 
  as 
  described 
  for 
  beak. 
  Elytra 
  of 
  females 
  

   inflated 
  as 
  in 
  Tosastes 
  ovalis 
  and 
  globularis, 
  while 
  in 
  males 
  very 
  little 
  wider 
  than 
  

   the 
  thorax; 
  elytral 
  striae 
  very 
  fine, 
  punctures 
  fine, 
  interstitial 
  punctures 
  irregular 
  

   but 
  as 
  large 
  as 
  strial 
  punctures; 
  surface 
  sometimes 
  mottled 
  with 
  brown. 
  Under- 
  

   sides 
  densely 
  squamose 
  and 
  clothed 
  as 
  above. 
  Last 
  ventral 
  segment 
  in 
  female 
  

   elongate 
  triangular, 
  apically 
  rounded, 
  and 
  longer 
  than 
  the 
  two 
  preceding 
  segments. 
  

   Legs 
  densely 
  squamose; 
  corbels 
  of 
  posterior 
  tibiae 
  with 
  a 
  double 
  row 
  of 
  spines, 
  

   inclosing 
  an 
  elliptical 
  squamose 
  area. 
  

  

  Female 
  genitalia 
  (fig. 
  63, 
  a, 
  b, 
  d). 
  — 
  Eighth 
  sternite 
  sharply 
  acute, 
  

   narrowly 
  rounded 
  at 
  apex, 
  apex 
  slightly 
  hairy. 
  Genital 
  tube 
  rather 
  

   lightly 
  chitinized, 
  laterally 
  compressed; 
  apical 
  plates 
  lacking; 
  coxites 
  

   large; 
  styli 
  large. 
  Receptaculum 
  seminis 
  with 
  cornu 
  fairly 
  thin, 
  

   irregular, 
  only 
  slightly 
  hooked; 
  nodulus 
  moderately 
  large; 
  ramus 
  

   subglobular; 
  ductus 
  receptaculi 
  thin, 
  not 
  curved 
  downward. 
  

  

  Male 
  genitalia 
  (fig. 
  63, 
  c). 
  — 
  Median 
  lobe 
  moderately 
  heavily 
  

   chitinized, 
  thick, 
  very 
  slightly 
  ciu-ved 
  in 
  profile, 
  dorsal 
  profile 
  not 
  

  

  