﻿274 
  W. 
  BLAXLAND 
  BRNHAM. 
  

  

  the 
  species 
  recently 
  described 
  by 
  Dr. 
  Micbaelsen 
  (5, 
  p. 
  139), 
  

   P. 
  kergnelenensis, 
  there 
  is 
  a 
  " 
  schlundkopf 
  ^' 
  similar 
  to 
  

   that 
  in 
  Enchytraeids 
  ; 
  this 
  is 
  certainly 
  not 
  the 
  case 
  in 
  

   P. 
  lacustris. 
  The 
  oesophagus, 
  immediately 
  behind 
  the 
  

   pharynx, 
  is 
  dilated, 
  but 
  short, 
  as 
  the 
  Septum 
  III/IV 
  is 
  

   thrust 
  back 
  by 
  the 
  pharynx 
  nearly 
  to 
  the 
  level 
  of 
  IV/Y. 
  

   The 
  oesophagus 
  passes 
  back 
  into 
  the 
  ninth 
  segment 
  (or 
  tenth, 
  

   in 
  one 
  case), 
  being 
  constricted 
  at 
  each 
  septum 
  and 
  moderately 
  

   distended 
  segmentally. 
  Its 
  epithelial 
  cells 
  are, 
  as 
  usual, 
  tall 
  

   and 
  ciliated. 
  

  

  In 
  the 
  ninth 
  (or 
  tenth) 
  segment 
  the 
  gut 
  suddenly 
  changes 
  

   its 
  character 
  ; 
  the 
  epithelium 
  becomes 
  flatter, 
  and 
  its 
  diameter 
  

   greatly 
  increases 
  so 
  as 
  nearly 
  to 
  fill 
  the 
  coelom 
  ; 
  it 
  is 
  here 
  

   filled 
  with 
  dirt, 
  and 
  is 
  constricted, 
  though 
  not 
  deeply, 
  by 
  the 
  

   septa. 
  

  

  I 
  have 
  but 
  few 
  notes 
  on 
  the 
  vascular 
  system, 
  owing 
  to 
  

   the 
  imperfect 
  manner 
  in 
  which 
  the 
  vessels 
  can 
  be 
  traced 
  by 
  

   sections 
  alone. 
  But 
  in 
  entire 
  specimens, 
  viewed 
  by 
  trans- 
  

   mitted 
  light, 
  the 
  following 
  facts 
  were 
  recorded 
  : 
  

  

  There 
  are 
  undulating 
  commissural 
  vessels 
  putting 
  the 
  

   dorsal 
  and 
  ventral 
  trunks 
  into 
  communication 
  in 
  Segments 
  

   V, 
  VI, 
  VII, 
  VIII, 
  but 
  I 
  could 
  not 
  detect 
  any 
  enlarged 
  hearts 
  

   nor 
  a 
  blood-gland, 
  either 
  in 
  mounted 
  individualsor 
  in 
  sections. 
  

  

  Excretory 
  System. 
  — 
  In 
  several 
  species 
  of 
  Phreo- 
  

   drilus 
  there 
  appears 
  to 
  be 
  only 
  one 
  pair 
  of 
  pregenital 
  

   nephridia, 
  but 
  these 
  extend 
  through 
  several 
  segments, 
  as 
  

   Beddard 
  pointed 
  out 
  (4) 
  in 
  his 
  account 
  of 
  P. 
  (Hespero- 
  

   drilus) 
  albus, 
  and 
  as 
  Michaelsen 
  finds 
  in 
  P. 
  kergnelen- 
  

   ensis; 
  but 
  in 
  P. 
  sub 
  terran 
  eus, 
  the 
  only 
  species 
  hitherto 
  

   described 
  from 
  New 
  Zealand, 
  Beddard 
  (2) 
  apparently 
  did 
  

   not 
  note 
  any 
  nephridia 
  anteriorly 
  to 
  the 
  fourteenth 
  segment. 
  

   In 
  the 
  present 
  species 
  I 
  observed 
  in 
  two 
  series 
  of 
  longitudinal 
  

   sections 
  a 
  nephridium 
  in 
  Segment 
  VII 
  and 
  another 
  in 
  Segment 
  

   X, 
  but 
  I 
  w^as 
  unable 
  to 
  trace 
  any 
  connection 
  between 
  these, 
  

   or 
  to 
  see 
  either 
  funnel 
  or 
  pore. 
  The 
  extreme 
  tenuity 
  of 
  the 
  

   species 
  renders 
  the 
  tracing 
  of 
  so 
  delicate 
  a 
  tube 
  as 
  a 
  neph- 
  

   ridium 
  very 
  diflScult. 
  

  

  