﻿86 
  Prof. 
  M'lntosh'a 
  Notes 
  from 
  tie 
  

  

  The 
  bristle-tufts 
  have 
  stout 
  simple 
  forms 
  with 
  tapering 
  tips, 
  

   which 
  have 
  traces 
  of 
  wings, 
  besides 
  those 
  with 
  spear-shaped 
  

   dilatations, 
  serrated 
  edges, 
  and 
  long 
  tapering 
  tips. 
  The 
  tufts 
  

   are 
  smaller 
  posteriorly, 
  but 
  do 
  not 
  differ 
  in 
  structure. 
  

  

  Each 
  of 
  the 
  hooks 
  presents 
  seven 
  teeth 
  below 
  the 
  crown, 
  

   then 
  follows 
  a 
  process 
  with 
  minute 
  teeth, 
  the 
  trend 
  of 
  Avhich 
  

   is 
  from 
  above 
  obliquely 
  outward, 
  whilst 
  its 
  prow 
  inferiorly 
  

   is 
  bluntly 
  conical. 
  The 
  shaft 
  of 
  the 
  hook 
  is 
  short. 
  

  

  The 
  caudal 
  process 
  is 
  tortoise-shaped, 
  and 
  usually 
  bent 
  at 
  

   more 
  than 
  a 
  right 
  angle 
  to 
  the 
  dorsum, 
  thus 
  making 
  a 
  small 
  

   angle 
  with 
  the 
  ventral 
  surface. 
  The 
  rudimentary 
  feet 
  pass 
  

   obliquely 
  upward 
  to 
  the 
  dorsal 
  keel^ 
  toward 
  the 
  end 
  of 
  which 
  

   is, 
  on 
  each 
  side, 
  a 
  considerable 
  row 
  of 
  caudal 
  hooks. 
  The 
  

   dorsal 
  surface 
  of 
  the 
  process 
  is 
  flatter 
  than 
  in 
  allied 
  forms, 
  a 
  

   median 
  keel 
  and 
  symmetrically 
  arranged 
  transverse 
  ridges 
  

   being 
  on 
  this 
  surface. 
  The 
  rim 
  is 
  not 
  much 
  elevated, 
  and 
  

   has 
  two 
  notches 
  beyond 
  the 
  hooks, 
  and 
  in 
  some 
  a 
  minute 
  

   papilla 
  or 
  two. 
  The 
  caudal 
  hooks 
  differ 
  from 
  those 
  of 
  

   any 
  other 
  form, 
  having 
  a 
  comparatively 
  straight 
  shaft, 
  

   which 
  taj^ers 
  toward 
  the 
  neck, 
  then 
  the 
  neck 
  bends 
  a 
  little 
  

   backward 
  and 
  gently 
  forward 
  at 
  the 
  tip 
  so 
  as 
  to 
  form 
  a 
  

   strong 
  point. 
  As 
  in 
  other 
  forms, 
  the 
  shaft 
  is 
  longitudinally 
  

   striated. 
  

  

  The 
  tube 
  is 
  large, 
  nearly 
  straight, 
  and 
  tapered 
  to 
  a 
  small 
  

   extremity. 
  Moreover.it 
  is 
  lined 
  in 
  some 
  by 
  a 
  comparatively 
  

   thick 
  internal 
  membrane, 
  which 
  readily 
  separates 
  from 
  

   the 
  firm 
  wall 
  in 
  the 
  preparations. 
  Its 
  masonry, 
  as 
  a 
  rule, 
  

   differs 
  from 
  that 
  of 
  Lctgis 
  or 
  Ampkictene 
  in 
  so 
  far 
  as 
  the 
  

   grains 
  are 
  smaller, 
  and, 
  even 
  though 
  in 
  some 
  the 
  surface 
  is 
  

   rendered 
  irregular 
  by 
  projecting 
  larger 
  grains, 
  the 
  general 
  

   effect 
  is 
  characteristic. 
  Typical 
  examples 
  on 
  sandy 
  ground 
  

   are 
  smooth 
  and 
  finely 
  grained, 
  no 
  separate 
  joints 
  being 
  

   distinguishable. 
  

  

  The 
  second 
  form 
  is 
  Amphiclene 
  awicoma, 
  O. 
  F. 
  Miiller, 
  

   which 
  is 
  generally 
  distributed 
  all 
  round 
  the 
  British 
  coasts 
  on 
  

   sandy 
  ground. 
  The 
  crown 
  in 
  this 
  species 
  bears 
  from 
  eleven 
  

   to 
  thirteen 
  paleolse, 
  which, 
  in 
  well-preserved 
  examples, 
  are 
  so 
  

   brittle 
  that 
  few 
  can 
  be 
  removed 
  entire. 
  They 
  are 
  fiattened 
  

   golden 
  bristles, 
  which 
  are 
  a 
  little 
  narrowed 
  at 
  the 
  base, 
  

   remain 
  of 
  uniform 
  diameter 
  for 
  some 
  distance, 
  and 
  then 
  

   taper 
  to 
  a 
  fine 
  point, 
  which 
  is 
  either 
  slightly 
  curved 
  or 
  

   l)oldly 
  bent 
  round 
  like 
  a 
  hook, 
  thus 
  differing, 
  for 
  instance, 
  

   from 
  those 
  of 
  Lagis 
  koreni, 
  which 
  are 
  coiled 
  after 
  the 
  

   manner 
  of 
  a 
  watch-spring. 
  The 
  dorsal 
  collar 
  at 
  the 
  margin 
  

   of 
  the 
  flattened 
  scabrous 
  area 
  above 
  the 
  paleolse 
  is 
  cut 
  into 
  

  

  