﻿Oli<jochcvta 
  of 
  Travancore. 
  503 
  

  

  The 
  posterior 
  third 
  of 
  the 
  body 
  is 
  coiled 
  and 
  distinctly 
  

   tetragonous 
  ; 
  the 
  transverse 
  section 
  of 
  the 
  tail 
  is 
  trapezoid, 
  

   the 
  largest 
  side 
  corresponding 
  to 
  the 
  dorsal 
  surface 
  of 
  the 
  

   body, 
  and 
  the 
  four 
  angles 
  to 
  the 
  bundles 
  of 
  the 
  seta?. 
  

  

  The 
  tail 
  is 
  smaller 
  than 
  the 
  cephalic 
  region. 
  The 
  anal 
  

   pore 
  appears 
  as 
  a 
  short 
  longitudinal 
  cleft 
  in 
  the 
  middle 
  

   dorsal 
  line 
  of 
  the 
  last 
  three 
  segments. 
  

  

  Colour 
  violet-grey, 
  clearer 
  and 
  with 
  a 
  tendency 
  to 
  rose-colour 
  

   at 
  the 
  clitellum, 
  especially 
  on 
  segments 
  .... 
  xvii.-xxxiii 
  

  

  The 
  body-wall 
  is 
  very 
  thin, 
  especially 
  at 
  the 
  tail, 
  and 
  

   internal 
  organs 
  can 
  be 
  seen 
  through 
  them 
  : 
  for 
  example, 
  the 
  

   spermatheca? 
  on 
  intersegmental 
  furrows 
  xiii.-xiv. 
  to 
  xvi.- 
  

   xvii. 
  in 
  mature 
  specimens. 
  

  

  The 
  seta? 
  are 
  paired, 
  but 
  not 
  strictly. 
  On 
  x. 
  segment 
  

   ma 
  nearly 
  = 
  2 
  ab, 
  ab 
  = 
  ^ 
  be, 
  cd=ab, 
  dd 
  a 
  little 
  larger 
  than 
  2 
  cd 
  

   or 
  than 
  aa. 
  On 
  the 
  posterior 
  half 
  of 
  the 
  body 
  the 
  seta? 
  are 
  

   more 
  strictly 
  paired: 
  aa 
  nearly 
  = 
  3 
  ab, 
  aa 
  = 
  bc, 
  ab 
  = 
  cd, 
  dd 
  

   nearly 
  = 
  4 
  cd. 
  

  

  All 
  mature 
  specimens 
  are 
  provided 
  with 
  unpaired 
  middle 
  

  

  ventral 
  papillae 
  on 
  segments 
  (xii.) 
  xiii. 
  to 
  the 
  xviii 
  

  

  xxiii. 
  (xxv.). 
  In 
  one 
  specimen 
  there 
  are 
  also 
  small 
  median 
  

   papilla? 
  on 
  segments 
  xxxiii.-xxxv. 
  

  

  Paired 
  lateral 
  papilla? 
  are 
  found 
  close 
  laterally 
  to 
  the 
  seta? 
  b 
  

   of 
  segments 
  xviii.-xxvi. 
  and 
  xxxiv.-xxxv. 
  Some 
  speci- 
  

   mens 
  are 
  also 
  provided 
  with 
  scattered 
  paired 
  papilla? 
  on 
  

   segments 
  xvi., 
  xvii., 
  and 
  xxvii.-xxxiii., 
  or 
  on 
  some 
  of 
  these 
  

   (PI. 
  XIII. 
  fig. 
  11). 
  

  

  All 
  the 
  papilla? 
  are 
  slightly 
  swollen, 
  more 
  so 
  near 
  the 
  

   posterior 
  than 
  the 
  anterior 
  margin 
  of 
  their 
  respective 
  seg- 
  

   ments. 
  Each 
  papilla 
  has 
  the 
  appearance 
  of 
  a 
  little 
  grey 
  

   round 
  stain, 
  which 
  is 
  provided 
  in 
  its 
  centre 
  with 
  a 
  small 
  

   whitish 
  circle 
  (PI. 
  XIII. 
  fig. 
  12). 
  

  

  The 
  clitellum 
  is 
  developed 
  all 
  round 
  the 
  body, 
  and 
  occupies 
  

   at 
  most 
  twenty-five 
  segments. 
  Indeed, 
  in 
  a 
  specimen 
  from 
  

   Achencoil 
  River 
  banks 
  it 
  extends 
  from 
  the 
  xv. 
  to 
  the 
  xxxix. 
  

   segment, 
  and 
  is 
  more 
  or 
  less 
  evident 
  from 
  its 
  rose-grey 
  

   colour, 
  and 
  for 
  the 
  slight 
  tumefaction, 
  which 
  is 
  in 
  relation 
  

   to 
  a 
  greater 
  quantity 
  of 
  glandular 
  cells 
  in 
  the 
  epidermis. 
  

  

  In 
  other 
  specimens 
  the 
  posterior 
  margin 
  of 
  the 
  clitellum 
  is 
  

   between 
  the 
  xxxv. 
  and 
  xl. 
  segments, 
  while 
  its 
  anterior 
  margin 
  

   seems 
  to 
  be 
  constantly 
  on 
  intersegmental 
  furrow 
  xvii.-xviii. 
  

   All 
  the 
  intersegmental 
  furrows 
  of 
  the 
  clitellum 
  are 
  recog- 
  

   nizable, 
  but 
  not 
  very 
  distinctly 
  those 
  included 
  between 
  the 
  

   xxv. 
  and 
  xxxiv. 
  segments 
  (PI. 
  XIII. 
  fig. 
  11). 
  

  

  The 
  clitellar 
  region 
  may 
  be 
  depressed, 
  at 
  least 
  partially, 
  

   and 
  its 
  lateral 
  margins, 
  often 
  rather 
  sharp, 
  are 
  provided 
  with 
  

  

  