﻿86 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.96 
  

  

  This 
  species 
  resembles 
  Fornax 
  mendax 
  Bonvouloir 
  and 
  Fornax 
  

   ohi'utus 
  Guerin, 
  but 
  it 
  differs 
  from 
  both 
  these 
  species 
  in 
  having 
  the 
  

   pronotum 
  transversely, 
  obliquely 
  depressed 
  behind 
  the 
  middle, 
  with 
  a 
  

   distinct 
  pitlike 
  depression 
  along 
  base 
  on 
  each 
  side 
  at 
  outer 
  angle 
  of 
  the 
  

   scutellum, 
  and 
  with 
  the 
  surface 
  finely 
  granulose, 
  and 
  the 
  elytra 
  finely 
  

   granulose 
  basally, 
  and 
  it 
  also 
  differs 
  from 
  ohrutus 
  Guerin 
  in 
  having 
  the 
  

   prosternal 
  process 
  deflexed 
  behind 
  the 
  anterior 
  coxae, 
  and 
  abruptly 
  

   narrower 
  to 
  the 
  tip, 
  which 
  is 
  acute. 
  

  

  Genus 
  PLESIOFORNAX 
  Bonvouloir 
  

  

  PLESIOFORNAX 
  NIGRINUS, 
  new 
  species 
  

  

  Narrowly 
  elongate, 
  subcylindrical, 
  strongly 
  shining, 
  black, 
  with 
  a 
  

   faint 
  bluish 
  or 
  greenish 
  tinge, 
  and 
  legs 
  brownish 
  black, 
  sparsely 
  

   clothed 
  with 
  short, 
  recumbent, 
  inconspicuous 
  hairs. 
  

  

  Head 
  strongly 
  convex, 
  without 
  distinct 
  depressions 
  or 
  carina, 
  rather 
  

   coarsely, 
  densely 
  punctate 
  ; 
  interocular 
  carina 
  not 
  elevated 
  or 
  extend- 
  

   ing 
  along 
  base 
  of 
  clypeus, 
  which 
  is 
  strongly 
  contracted 
  at 
  base, 
  its 
  

   width 
  there 
  being 
  less 
  than 
  half 
  the 
  distance 
  to 
  eye, 
  and 
  broadly, 
  sin- 
  

   uately 
  rounded 
  in 
  front. 
  Antenna 
  slender, 
  more 
  robust 
  toward 
  tip, 
  

   extending 
  to 
  basal 
  fourth 
  of 
  elytra, 
  basal 
  segments 
  slightly 
  longitu- 
  

   dinally 
  carinate; 
  segment 
  2 
  as 
  long 
  as 
  segment 
  5; 
  segment 
  3 
  much 
  

   longer 
  than 
  either 
  2 
  or 
  4 
  ; 
  segment 
  4 
  longer 
  than 
  wide, 
  more 
  than 
  half 
  

   as 
  long 
  as 
  5, 
  the 
  following 
  segments 
  becoming 
  gradually 
  longer. 
  

  

  Pronotum 
  as 
  long 
  as 
  wide, 
  strongly 
  convex; 
  sides 
  parallel 
  along 
  

   basal 
  two-thirds, 
  feebly, 
  arcuately 
  narrowed 
  along 
  apical 
  third 
  ; 
  sur- 
  

   face 
  very 
  sparsely, 
  finely 
  punctate, 
  with 
  a 
  median, 
  longitudinal 
  de- 
  

   pression 
  extending 
  from 
  base 
  to 
  middle 
  of 
  pronotum, 
  the 
  depression 
  

   becoming 
  broader 
  and 
  deeper 
  posteriorly. 
  

  

  Elytra 
  strongly 
  convex; 
  sides 
  parallel 
  from 
  base 
  to 
  apical 
  third, 
  

   then 
  arcuately 
  narrowed 
  to 
  tips, 
  which 
  are 
  conjointly 
  broadly 
  

   rounded 
  ; 
  surface 
  rather 
  coarsely, 
  not 
  very 
  densely, 
  irregularly 
  punc- 
  

   tate, 
  not 
  striate. 
  

  

  Abdomen 
  finely, 
  densely 
  punctate, 
  more 
  confluently 
  toward 
  apex 
  

   of 
  last 
  sternite, 
  which 
  is 
  obtusely 
  angulated. 
  Presternum 
  sparsely 
  

   punctate 
  on 
  median 
  part, 
  densely 
  on 
  propleural 
  triangle, 
  which 
  is 
  

   distinctly 
  longer 
  than 
  wide 
  at 
  base 
  ; 
  antennal 
  groove 
  deep, 
  smooth, 
  and 
  

   shining 
  in 
  its 
  entire 
  length; 
  prosternal 
  process 
  broad, 
  flat, 
  without 
  

   depressions, 
  sides 
  obliquely 
  converging 
  to 
  apex, 
  which 
  is 
  broadly 
  

   rounded. 
  Posterior 
  tarsus 
  with 
  first 
  segment 
  as 
  long 
  as 
  following 
  

   segments 
  united 
  ; 
  tarsal 
  claws 
  long, 
  slender, 
  slightly 
  swollen 
  near 
  base, 
  

   but 
  not 
  toothed. 
  

  

  Length 
  11-13 
  mm., 
  width 
  2.5-2.8 
  mm. 
  

  

  Type 
  locality. 
  — 
  Rio 
  Hondo, 
  Costa 
  Rica. 
  

  

  Type 
  and 
  paratypes.—V.S.^M. 
  No. 
  57169. 
  

  

  