﻿The 
  British 
  Species 
  of 
  Andrena 
  and 
  Nomada. 
  285 
  

  

  40. 
  (37) 
  Mandibles 
  always 
  with 
  a 
  tooth 
  before 
  the 
  apex. 
  

  

  41. 
  (52) 
  Mandibles 
  at 
  the 
  base 
  always 
  armed 
  with 
  a 
  distinct 
  angular 
  

  

  tooth 
  oh 
  the 
  lower 
  margin, 
  the 
  mandibles 
  themselves 
  

   always 
  very 
  long, 
  falcate, 
  strongly 
  crossing 
  at 
  the 
  tips. 
  

  

  42. 
  (43) 
  Third 
  joint 
  of 
  the 
  antennae 
  very 
  elongate, 
  about 
  twice 
  

  

  as 
  long 
  as 
  the 
  short 
  4th 
  joint, 
  this 
  latter 
  nearly 
  

   square 
  in 
  outline 
  (thorax 
  and 
  abdomen 
  in 
  fresh 
  examples 
  

   with 
  fulvous 
  hairs). 
  fulva. 
  

  

  43. 
  (42) 
  Third 
  joint 
  sometimes 
  considerably 
  longer 
  than, 
  but 
  not 
  

  

  nearly 
  twice 
  as 
  long 
  as, 
  the 
  4th, 
  and 
  the 
  latter 
  is 
  itself 
  

   quite 
  elongate. 
  

  

  44. 
  (49) 
  Propodeum 
  clothed 
  with 
  pale 
  fulvous 
  hairs, 
  fading 
  to 
  pale 
  

  

  ochreous 
  or 
  whitish 
  ; 
  very 
  few 
  or 
  no 
  black 
  hairs 
  ; 
  thorax 
  

   above 
  in 
  fresh 
  specimens 
  with 
  fulvous 
  clothing. 
  

  

  45. 
  (48) 
  Hind 
  tarsi 
  often 
  entirely 
  or 
  at 
  least 
  with 
  the 
  apical 
  joints 
  

  

  clear 
  testaceous; 
  or 
  else 
  the 
  mandibular 
  basal 
  tooth 
  is 
  

   short 
  and 
  wide, 
  forming 
  a 
  simple 
  angulation. 
  

  

  46. 
  (47) 
  Ventral 
  abdominal 
  segments 
  with 
  excessively 
  dense 
  fringes 
  

  

  of 
  white 
  or 
  almost 
  white 
  decumbent 
  hairs, 
  so 
  that 
  the 
  

   abdomen 
  beneath 
  has 
  very 
  conspicuous 
  and 
  beautiful 
  

   dense 
  bands; 
  tubercle 
  of 
  labrum, 
  viewed 
  from 
  above 
  

   when 
  the 
  clypeus 
  is 
  in 
  the 
  horizontal 
  plane, 
  narrower 
  

   in 
  comparison 
  to 
  the 
  width 
  between 
  the 
  angles 
  of 
  

   the 
  front 
  margin 
  of 
  the 
  clypeus, 
  and 
  not 
  distinctly 
  

   emarginate 
  helvokt. 
  

  

  47. 
  (46) 
  Ventral 
  abdominal 
  segments 
  with 
  the 
  fringes 
  less 
  dense 
  

  

  and 
  distinct, 
  the 
  tubercle 
  of 
  the 
  labrum 
  wide 
  and 
  dis- 
  

   tinctly 
  emarginate. 
  fucata. 
  

  

  48. 
  (45) 
  Hind 
  tarsi 
  blackish 
  or 
  dark 
  brown; 
  mandibular 
  basal 
  

  

  tooth 
  comparatively 
  long 
  and 
  narrow, 
  stiongly 
  promi- 
  

   nent, 
  except 
  as 
  an 
  unusual 
  aberration. 
  . 
  lapponica. 
  

  

  49. 
  (44) 
  Propodeum 
  clothed 
  with 
  pale 
  hairs 
  and 
  on 
  some 
  part 
  at 
  

  

  least 
  with 
  many 
  black 
  hairs, 
  the 
  whole 
  thorax 
  above 
  

   in 
  fresh 
  examples 
  much 
  less 
  bright, 
  more 
  grey 
  than 
  in 
  

   the 
  preceding. 
  

  

  50. 
  (51) 
  Process 
  of 
  8th 
  ventral 
  segment 
  of 
  the 
  abdomen 
  distinctly 
  

  

  emarginate 
  at 
  apex; 
  mandibular 
  tooth 
  usually 
  broader 
  

   and 
  blunter 
  and 
  the 
  3rd 
  antennal 
  joint 
  rather 
  less 
  elon- 
  

   gate 
  than 
  in 
  apicata 
  praecox. 
  

  

  51. 
  (50) 
  Process 
  of 
  8th 
  ventral 
  segment 
  rounded 
  or 
  truncate 
  at 
  

  

  apex, 
  not 
  distinctly 
  emarginate 
  apicata. 
  

  

  52. 
  (41) 
  Mandibles 
  at 
  the 
  base 
  not 
  armed 
  with 
  a 
  distinct 
  tooth 
  on 
  

  

  the 
  lower 
  margin, 
  but 
  at 
  most 
  with 
  the 
  margin 
  somewhat 
  

   rounded 
  at 
  that 
  point. 
  

  

  