﻿236 
  Mr. 
  R. 
  C. 
  L. 
  Perkins 
  on 
  

  

  brooded 
  even 
  in 
  the 
  south, 
  while 
  some 
  which 
  are 
  so 
  on 
  the 
  

   Continent 
  have 
  but 
  one 
  brood 
  with 
  us. 
  This 
  may 
  be 
  the 
  

   case, 
  even 
  though 
  the 
  host 
  be 
  regularly 
  double-brooded. 
  

  

  Several 
  of 
  our 
  species 
  are 
  irregularly 
  double-brooded, 
  

   e. 
  g., 
  N 
  . 
  flavoguttata 
  and 
  fabriciana, 
  both 
  of 
  which 
  some- 
  

   times 
  yield 
  an 
  abundant 
  second 
  generation. 
  So 
  too 
  does 
  

   N. 
  lineola 
  in 
  some 
  seasons, 
  and 
  perhaps 
  generally 
  in 
  the 
  

   extreme 
  south. 
  N. 
  marshamella, 
  when 
  parasitic 
  on 
  

   A. 
  spinigera 
  frequently, 
  and 
  when 
  on 
  A. 
  trimmerana 
  

   (Auct.) 
  occasionally, 
  yields 
  a 
  summer 
  brood; 
  in 
  the 
  latter 
  

   case 
  generally 
  partial 
  and 
  represented 
  by 
  only 
  a 
  few 
  in- 
  

   dividuals, 
  but 
  in 
  the 
  former 
  sometimes 
  a 
  copious 
  one, 
  

   females 
  of 
  which 
  I 
  have 
  taken 
  in 
  plenty 
  entering 
  the 
  

   burrows 
  of 
  the 
  second 
  brood 
  of 
  its 
  host 
  — 
  the 
  form 
  named 
  

   A. 
  anglica 
  by 
  Alfken. 
  

  

  In 
  August 
  1886, 
  on 
  the 
  south 
  coast 
  I 
  met 
  with 
  a 
  second 
  

   brood 
  of 
  A. 
  goodeniana 
  in 
  almost 
  incredible 
  numbers, 
  but 
  

   strangely 
  enough 
  have 
  never 
  since 
  met 
  with 
  a 
  single 
  ex- 
  

   ample 
  of 
  such, 
  though 
  Hallett 
  has 
  observed 
  a 
  copious 
  

   summer 
  generation. 
  I 
  have 
  seen 
  an 
  example 
  of 
  a 
  second 
  

   brood 
  of 
  N. 
  mficornis 
  from 
  Ireland, 
  but 
  not 
  from 
  elsewhere. 
  

  

  These 
  examples 
  of 
  a 
  second 
  brood 
  are 
  in 
  the 
  case 
  of 
  

   A. 
  fabriciana 
  and 
  flavoguttata 
  much 
  darker 
  than 
  the 
  first, 
  

   as 
  may 
  be 
  seen 
  when 
  a 
  series 
  of 
  examples 
  is 
  placed 
  side 
  

   by 
  side; 
  indeed, 
  that 
  of 
  the 
  latter 
  has, 
  I 
  believe, 
  been 
  

   given 
  a 
  special 
  name 
  — 
  var. 
  hoeppneii 
  — 
  by 
  Alfken. 
  

  

  The 
  genus 
  Sphecodes 
  is 
  essentially 
  a 
  parasite 
  on 
  Halictus, 
  

   but 
  three 
  species 
  appear 
  to 
  be 
  strictly 
  attached 
  to 
  Andrena, 
  

   though 
  the 
  evidence 
  is 
  not 
  so 
  absolutely 
  conclusive 
  as 
  

   one 
  could 
  wish. 
  Of 
  these 
  species 
  S. 
  rubicundus 
  is 
  said 
  to 
  

   be 
  a 
  parasite 
  on 
  A. 
  labialis 
  both 
  here 
  and 
  on 
  the 
  Continent, 
  

   and 
  certainly 
  has 
  been 
  taken 
  in 
  closest 
  company 
  with 
  

   that 
  Andrena 
  in 
  Suffolk, 
  Hampshire, 
  Cambridge, 
  etc., 
  so 
  

   that 
  there 
  would 
  appear 
  to 
  be 
  no 
  reason 
  to 
  doubt 
  this 
  

   association. 
  

  

  S. 
  reticulatus 
  is 
  said 
  on 
  the 
  Continent 
  to 
  be 
  attached 
  to 
  

   A. 
  argentata, 
  and 
  certainly 
  in 
  localities 
  where 
  it 
  occurs 
  in 
  

   this 
  country, 
  when 
  extensive 
  search 
  has 
  been 
  made, 
  this 
  

   Andrena 
  has 
  always, 
  I 
  think, 
  been 
  met 
  with. 
  ' 
  Halictus 
  

   prasinvs 
  has 
  also 
  been 
  suggested 
  as 
  a 
  host 
  for 
  the 
  Sphecodes, 
  

   and, 
  as 
  it 
  happens, 
  this 
  Halictus 
  frequently 
  abounds 
  in 
  the 
  

   very 
  same 
  localities 
  as 
  the 
  Andrena. 
  On 
  the 
  other 
  hand, 
  

   H. 
  prasinus 
  occurs 
  over 
  a 
  wide 
  area 
  of 
  distribution 
  in 
  

   Britain, 
  from 
  which 
  the 
  Sphecodes 
  has 
  never 
  been 
  obtained, 
  

  

  