﻿316 
  Mr. 
  R. 
  C. 
  L. 
  Perkins 
  on 
  Andrena 
  and 
  Nomada. 
  

  

  has 
  lathhuriana. 
  N.fucata 
  and 
  goodeniana 
  are 
  members 
  of 
  

   a 
  natural 
  group 
  ; 
  but 
  it 
  contains 
  no 
  other 
  British 
  species. 
  

  

  Most 
  of 
  our 
  species 
  belong 
  to 
  the 
  ruficornis 
  group, 
  

   containing 
  besides 
  ruficornis 
  itself, 
  flava, 
  signata, 
  leucoph- 
  

   thahna 
  xanthosticta 
  bucephalae 
  and 
  hillana, 
  and, 
  at 
  any 
  

   rate 
  in 
  dealing 
  with 
  our 
  small 
  fauna, 
  I 
  should 
  also 
  include 
  

   in 
  it 
  the 
  following 
  : 
  lineola 
  and 
  marshamella, 
  baccata, 
  

   bifida, 
  conjungens, 
  flavoguttata 
  and 
  fabriciana. 
  N. 
  furva 
  is 
  

   an 
  isolated 
  form. 
  

  

  A 
  series 
  of 
  examples 
  of 
  N. 
  marshamella 
  $ 
  belonging 
  to 
  

   the 
  second 
  generation 
  and 
  taken 
  at 
  the 
  burrows 
  of 
  the 
  

   summer 
  brood 
  of 
  Andrena 
  spinigera 
  is 
  interesting 
  in 
  having 
  

   the 
  propodeum 
  much 
  less 
  clothed 
  than 
  in 
  specimens 
  of 
  

   the 
  first 
  brood. 
  In 
  some 
  localities 
  examples 
  of 
  the 
  females 
  

   of 
  N. 
  lineola 
  have 
  the 
  flagellar 
  joints 
  of 
  the 
  antennae 
  

   entirely 
  fulvescent, 
  none 
  of 
  these 
  being 
  darkened 
  behind. 
  

   I 
  have 
  not 
  found 
  this 
  variety 
  amongst 
  numerous 
  examples 
  

   taken 
  at 
  the 
  burrows 
  of 
  Andrena 
  bi^nactdata 
  and 
  carbonaria, 
  

   and 
  suspect 
  that 
  it 
  may 
  only 
  occur 
  in 
  those 
  attached 
  to 
  

   A. 
  tibialis, 
  but 
  it 
  is 
  possibly 
  due 
  rather 
  to 
  locality 
  than 
  

   host. 
  

  

  In 
  conclusion 
  I 
  must 
  express 
  my 
  thanks 
  to 
  my 
  friends, 
  

   the 
  Rev. 
  F. 
  D. 
  Morice 
  and 
  Mr. 
  H. 
  M. 
  Hallett, 
  to 
  whom 
  I 
  

   am 
  indebted 
  for 
  many 
  valuable 
  corrections 
  and 
  suggestions, 
  

   which 
  I 
  have 
  adopted 
  in 
  this 
  paper, 
  and 
  who 
  have 
  put 
  

   themselves 
  to 
  the 
  great 
  trouble 
  (as 
  I 
  have 
  previously 
  

   mentioned) 
  of 
  looking 
  into 
  the 
  validity 
  of 
  many 
  of 
  the 
  

   specific 
  characters, 
  given 
  in 
  the 
  tables 
  of 
  Andrena. 
  I 
  

   regret 
  that 
  I 
  have 
  been 
  unable 
  to 
  make 
  these 
  more 
  simple, 
  

   but 
  without 
  disregarding 
  variation, 
  I 
  do 
  not 
  see 
  how 
  this 
  

   can 
  be 
  done. 
  

  

  So 
  far 
  as 
  possible 
  I 
  have 
  endeavoured 
  to 
  supplement 
  

   the 
  standard 
  works 
  of 
  the 
  late 
  Edward 
  Saunders 
  by 
  using 
  

   characters 
  which 
  have 
  previously 
  been 
  more 
  or 
  less 
  over- 
  

   looked 
  or 
  disregarded. 
  I 
  cannot 
  sufficiently 
  express 
  how 
  

   much 
  I 
  am 
  indebted 
  to 
  our 
  former 
  leading 
  authority 
  on 
  

   this 
  group 
  of 
  insects 
  not 
  only 
  for 
  constant 
  help 
  by 
  means 
  

   of 
  correspondence 
  in 
  the 
  early 
  days 
  of 
  my 
  study, 
  but 
  also 
  

   for 
  the 
  frequent 
  loan 
  of 
  his 
  whole 
  series 
  of 
  difficult 
  species, 
  

   including 
  the 
  actual 
  specimens, 
  from 
  which 
  he 
  drew 
  up 
  

   his 
  descriptions. 
  

  

  