﻿84 
  Prof. 
  M'lntosh's 
  Notes 
  from 
  tJie 
  

  

  and 
  Claparede's, 
  have 
  each 
  distinctive 
  features, 
  yet 
  some 
  of 
  

   these 
  may 
  be 
  due 
  to 
  imperfections 
  in 
  observation 
  and 
  to 
  

   variation. 
  Certainly 
  the 
  bristles 
  and 
  hooks 
  are 
  very 
  similar. 
  

   '^Ihe 
  occurrence 
  of 
  mature 
  females 
  in 
  Claparede's 
  small 
  form, 
  

   also 
  recently 
  procured 
  by 
  INIr. 
  Southern, 
  may 
  be 
  connected 
  

   with 
  racial 
  distinctions. 
  Moreover, 
  the 
  inconspicuous 
  

   cephalic 
  ridge 
  and 
  the 
  presence 
  of 
  eyes 
  in 
  it, 
  and 
  their 
  

   absence 
  in 
  Malmgren's 
  form, 
  is 
  another 
  source 
  of 
  dubiety. 
  

   The 
  Canadian, 
  the 
  Arctic 
  examples 
  procured 
  by 
  the 
  ' 
  Valo- 
  

   rous,' 
  and 
  the 
  P. 
  phimosa 
  of 
  Sars 
  all 
  present 
  such 
  a 
  ridge, 
  

   and 
  it 
  is 
  possible 
  Malmgren 
  may 
  have 
  overlooked 
  it, 
  since 
  

   in 
  some 
  it 
  is 
  inconspicuous. 
  

  

  (3) 
  On 
  the 
  British 
  Amphititenidse. 
  

  

  Tlie 
  British 
  Amphictenidse 
  comprised 
  but 
  two 
  species 
  

   in 
  Dr. 
  Johnston's 
  ' 
  Catalogue 
  of 
  Worms 
  in 
  the 
  British 
  

   Museum/ 
  viz. 
  Pectinaria 
  helgica, 
  Pallas, 
  and 
  P. 
  granulata, 
  L. 
  

   = 
  AmpJdctene 
  auricoma, 
  O. 
  F. 
  Miiller, 
  The 
  latter 
  species 
  

   and 
  Layis 
  koreni, 
  Malmgren, 
  again, 
  were 
  the 
  only 
  forms 
  

   entered 
  in 
  the 
  ' 
  F'auna 
  of 
  Plymovith' 
  (1904), 
  but 
  Mr. 
  Craw- 
  

   shay 
  in 
  1912 
  added 
  a 
  third, 
  viz., 
  Petta 
  pusilla, 
  Malmgren. 
  

   Two 
  species 
  occur 
  in 
  Mr. 
  Southern's 
  ' 
  Annelids 
  of 
  Dublin 
  

   Bay,' 
  viz., 
  those 
  mentioned 
  by 
  Dr. 
  Johnston. 
  

  

  The 
  first 
  species 
  is 
  Pectinaria 
  belgica, 
  Pallas, 
  from 
  various 
  

   parts 
  of 
  tlie 
  English, 
  Scotcli, 
  and 
  Irish 
  coasts. 
  

  

  The 
  crown 
  in 
  this 
  species 
  has 
  ten 
  to 
  fourteen 
  paleolae, 
  which 
  

   are 
  broader 
  than 
  those 
  of 
  Lagis 
  koreni, 
  and, 
  as 
  P. 
  belgica 
  is 
  

   often 
  largei', 
  they 
  are 
  stronger 
  and 
  more 
  individualized, 
  but 
  

   their 
  curves 
  are 
  similar, 
  the 
  convexity 
  being 
  ventral. 
  They 
  

   dilate 
  a 
  little 
  above 
  the 
  base, 
  and 
  then 
  tajjer 
  to 
  a 
  very 
  delicate 
  

   liair-like 
  tip, 
  which, 
  from 
  the 
  lines 
  at 
  its 
  sides, 
  would 
  seem 
  to 
  

   indicate 
  relationship 
  with 
  a 
  winged 
  bristle. 
  Friction, 
  how- 
  

   ever, 
  removes 
  the 
  delicate 
  extremity 
  in 
  some. 
  The 
  outer 
  

   paleola 
  is 
  shorter 
  than 
  the 
  adjoining 
  one, 
  whil!>t 
  the 
  two 
  

   inner 
  api 
  ear 
  also 
  to 
  be 
  smaller 
  in 
  most 
  examples. 
  In 
  the 
  

   largest 
  example 
  from 
  British 
  waters 
  in 
  my 
  collection, 
  viz. 
  

   from 
  Loch 
  Linnhe, 
  fourteen 
  paleolse 
  occurred 
  on 
  the 
  left 
  and 
  

   ten 
  on 
  the 
  right. 
  Above 
  the 
  paleolae 
  is 
  the 
  tough, 
  firm, 
  and 
  

   slightly 
  corrugated 
  surface 
  of 
  the 
  crown, 
  -which 
  has 
  a 
  pro- 
  

   portionally 
  broader 
  rim 
  than 
  in 
  L. 
  koreni. 
  Having 
  reached 
  

   its 
  greatest 
  diameter 
  laterally, 
  it 
  curves 
  ventrally 
  a 
  little 
  

   within 
  the 
  edge 
  of 
  the 
  paIeola3, 
  and 
  ends 
  at 
  the 
  long 
  anterior 
  

   cirrus. 
  The 
  margin 
  dorsally 
  and 
  laterally 
  is 
  smooth, 
  but 
  on 
  

   the 
  ventral 
  curve 
  to 
  the 
  paleolse 
  it 
  has 
  one 
  or 
  two 
  small 
  

   papillne. 
  

  

  