﻿Genera 
  of 
  Oriental 
  Barbels. 
  235 
  

  

  wliich 
  have 
  long 
  been 
  a 
  difficulty, 
  and 
  scarcely 
  any 
  two 
  

   naturalists 
  have 
  adopted 
  the 
  same 
  generic 
  divisions. 
  It 
  is 
  

   unnecessary 
  to 
  enter 
  at 
  any 
  length 
  into 
  the 
  various 
  arrange- 
  

   ments 
  that 
  have 
  been 
  adopted, 
  and 
  it 
  will 
  suffice 
  to 
  notice 
  

   those 
  employed 
  by 
  a 
  few 
  of 
  the 
  principal 
  writers 
  who 
  have 
  

   dealt 
  with 
  the 
  family. 
  

  

  In 
  1849 
  all 
  the 
  species 
  belonging 
  to 
  the 
  five 
  genera 
  men- 
  

   tioned, 
  so 
  far 
  as 
  they 
  were 
  then 
  known, 
  Avere 
  included 
  by 
  

   Mr. 
  G. 
  R. 
  Gray 
  in 
  his 
  genus 
  Megalahna 
  (Gen. 
  Birds, 
  ii. 
  

   p. 
  429). 
  In 
  1854 
  Bonaparte, 
  in 
  the 
  'Conspectus 
  Volucrum 
  

   Zygodactylorum/ 
  divided 
  the 
  members 
  of 
  Gray^s 
  genus 
  

   Megalama 
  into 
  two 
  genera, 
  Bucco 
  and 
  Megalama, 
  the 
  latter 
  

   being 
  subdivided 
  into 
  four 
  subgenera, 
  MegaJcema, 
  Chotorhea, 
  

   Cyanops, 
  and 
  Xantholcema, 
  the 
  last 
  three 
  terms 
  being 
  then 
  

   proposed 
  as 
  new. 
  In 
  the 
  ' 
  Monograph 
  of 
  the 
  Capitonidse 
  ' 
  

   (1871), 
  Messrs. 
  C. 
  H. 
  T. 
  and 
  G. 
  F. 
  L. 
  Marshall 
  reunited 
  

   four 
  of 
  Bonaparte's 
  genera 
  and 
  subgenera 
  under 
  Gray's 
  

   generic 
  name 
  Megalama 
  [Bucco 
  had 
  been 
  shown 
  to 
  be 
  some- 
  

   thing 
  very 
  different), 
  Xantholama 
  alone 
  being 
  kept 
  separate. 
  

   This 
  distinction 
  of 
  Xanlholama, 
  of 
  which 
  the 
  type 
  is 
  X 
  hcenia- 
  

   tocephala, 
  the 
  common 
  " 
  Coppersmith 
  '' 
  of 
  India, 
  has 
  been 
  

   generally 
  accepted, 
  as 
  both 
  the 
  bill 
  and 
  the 
  wing 
  are 
  different 
  

   in 
  form 
  from 
  those 
  of 
  the 
  species 
  retained 
  by 
  Messrs. 
  Marshall 
  

   in 
  Megalcema. 
  

  

  But 
  although 
  all 
  the 
  species 
  of 
  Bonaparte's 
  Bucco, 
  Mega- 
  

   lama, 
  Chotorliea, 
  and 
  Cyanops 
  were 
  arranged 
  in 
  one 
  genus 
  

   in 
  the 
  Monograph, 
  that 
  genus 
  in 
  the 
  key 
  (pp. 
  xxvi-xxvii) 
  

   was 
  divided 
  into 
  three 
  sections, 
  none 
  of 
  which, 
  except 
  the 
  

   first, 
  corresponded 
  with 
  any 
  of 
  Bonaparte's 
  genera. 
  The 
  

   first 
  of 
  these 
  sections, 
  distinguished 
  as 
  " 
  Sect, 
  a, 
  maxima, 
  

   dorso 
  olivascenti-brunneo,'' 
  corresponded 
  to 
  Bonaparte's 
  

   Bucco, 
  and 
  contained 
  only 
  one 
  species, 
  M. 
  virens 
  (the 
  Hima- 
  

   layan 
  iV/e^fl/«wrt 
  marshallorum 
  was 
  subsequently 
  distinguished 
  

   from 
  typical 
  M. 
  virens 
  by 
  Swinhoe) 
  ; 
  the 
  second 
  section, 
  thus 
  

   characterized, 
  " 
  b, 
  virides, 
  capite 
  versicolori," 
  comprised 
  the 
  

   Megalcema, 
  Cyanops, 
  and 
  part 
  of 
  the 
  Chotorhea 
  of 
  Bonaparte 
  ; 
  

   whilst 
  the 
  third, 
  with 
  these 
  characters, 
  " 
  c, 
  virides, 
  capite 
  

   brumieo 
  vel 
  albo 
  striate,'' 
  contained 
  a 
  well-known 
  group 
  of 
  

  

  