﻿88 
  Prof. 
  M'lutosli's 
  Notes 
  from 
  the 
  

  

  So 
  far 
  as 
  these 
  parts 
  show, 
  tliree 
  segments 
  would 
  thus 
  

   seem 
  to 
  peitain 
  to 
  the 
  collar-region^ 
  viz. 
  that 
  o£ 
  the 
  second 
  

   long 
  cirrus 
  and 
  the 
  two 
  branchial 
  segments. 
  

  

  The 
  next 
  region 
  of 
  the 
  body 
  consists 
  of 
  three 
  bristled 
  seg- 
  

   ments, 
  devoid 
  of 
  hooks 
  as 
  in 
  allied 
  forms. 
  The 
  appearance 
  

   of 
  these, 
  however, 
  suggests 
  a 
  subdivision, 
  for 
  the 
  two 
  anterior 
  

   have 
  the 
  thick 
  glandular 
  ridges, 
  the 
  first 
  with 
  a 
  single 
  central 
  

   division 
  and 
  the 
  second 
  with 
  two 
  central 
  divisions: 
  whereas 
  

   the 
  third 
  has 
  only 
  a 
  long, 
  slender, 
  non-glandular 
  ridge, 
  as 
  in 
  

   those 
  which 
  follow. 
  This 
  region 
  appears 
  to 
  be, 
  on 
  the 
  whole, 
  

   considerably 
  fon 
  shortened 
  in 
  contrast 
  with 
  Lagis. 
  The 
  

   first 
  two 
  tufts 
  are 
  very 
  small, 
  and 
  they 
  arise 
  from 
  the 
  non- 
  

   glandular 
  or 
  dorsal 
  part 
  of 
  the 
  ridge. 
  The 
  third 
  is 
  consider- 
  

   ably 
  larger, 
  and 
  is 
  usually 
  closely 
  applied 
  to 
  the 
  surface 
  of 
  

   the 
  dorso-lateral 
  region. 
  Each 
  tuft 
  has 
  the 
  stout, 
  tapering, 
  

   simple 
  bristles 
  with 
  traces 
  of 
  wings 
  distally 
  below 
  the 
  

   tapered 
  point, 
  and 
  all 
  have, 
  in 
  addition, 
  a 
  few 
  in 
  which 
  the 
  

   spear-like 
  dilatation 
  at 
  the 
  tip 
  is 
  present, 
  with 
  its 
  tapering 
  

   hair-like 
  point 
  and 
  serrated 
  edge. 
  All 
  these 
  bristles 
  have 
  a 
  

   peculiar 
  ring-like 
  dilatation 
  at 
  the 
  base. 
  

  

  The 
  third 
  region 
  is 
  characterised 
  by 
  the 
  great 
  development 
  

   of 
  the 
  lateral 
  lamella? 
  for 
  the 
  hooks, 
  as 
  well 
  as 
  for 
  the 
  long 
  

   and 
  powerful 
  bristles 
  at 
  the 
  dorsal 
  edge. 
  All 
  the 
  latter 
  are 
  

   very 
  powerful 
  anteriorly, 
  dilating 
  from 
  the 
  base 
  upward 
  

   until 
  fidl 
  diameter 
  is 
  attained, 
  and 
  then 
  tapering 
  to 
  a 
  delicate 
  

   hair-like 
  tip. 
  Besides 
  these 
  are 
  the 
  bristles 
  with 
  the 
  spear- 
  

   shaped 
  enlargement 
  and 
  the 
  linely 
  tapered 
  tips, 
  the 
  shafts 
  

   being 
  also 
  robust. 
  The 
  posterior 
  bristles 
  are 
  considerably 
  

   smaller, 
  but 
  they 
  keep 
  to 
  the 
  same 
  type, 
  those 
  with 
  the 
  

   spear-shaped 
  tips 
  being 
  proportionally 
  longer. 
  

  

  The 
  caudal 
  hooks 
  are 
  situated 
  on 
  each 
  side 
  of 
  a 
  small 
  keel 
  

   (notched 
  at 
  its 
  free 
  end), 
  which 
  marks 
  the 
  median 
  dorsal 
  

   region 
  of 
  the 
  caudal 
  appendage. 
  They 
  are 
  distinguished 
  by 
  

   their 
  comparatively 
  great 
  length 
  and 
  straightness, 
  by 
  the 
  

   rapid 
  diminution 
  at 
  the 
  neck, 
  and 
  by 
  the 
  abrupt 
  curve 
  and 
  

   sharp 
  condition 
  of 
  the 
  hook 
  at 
  the 
  tip. 
  The 
  edge 
  of 
  the 
  

   process 
  is 
  deeply 
  and 
  symmetrically 
  notched, 
  usually 
  curved 
  

   ventrally, 
  and 
  the 
  dorsal 
  lip 
  of 
  the 
  vent 
  is 
  prolonged 
  as 
  a 
  

   somewhat 
  flattened 
  conical 
  process, 
  with 
  a 
  dorsal 
  papilla 
  on 
  

   its 
  surface, 
  which 
  curves 
  beyond 
  the 
  split 
  ventral 
  lip. 
  The 
  

   dorsal 
  surface 
  of 
  the 
  process 
  is 
  concave, 
  forming 
  a 
  deep 
  

   groove, 
  whilst 
  the 
  A^entral 
  is 
  convex 
  and 
  grooved 
  by 
  oblique 
  

   furrows 
  directed 
  outward 
  and 
  backward. 
  It 
  seems 
  to 
  be 
  

   easily 
  regenerated, 
  even 
  before 
  the 
  bristled 
  segments 
  neces- 
  

   sary 
  to 
  complete 
  the 
  series 
  are 
  formed, 
  and 
  thus 
  some 
  

   examples 
  are 
  peculiarly 
  short 
  and 
  broad, 
  the 
  tapered 
  posterior 
  

  

  