﻿CLASSIFICATION, 
  ETC. 
  OF 
  HAMILTON 
  AND 
  CHEMUNG 
  SERIES 
  149 
  

   ANKELIDA 
  

  

  Planolites 
  Nicholson, 
  1873, 
  Proc. 
  Roy 
  Soc, 
  London, 
  p. 
  289 
  

   Planolites 
  clarkii 
  nov. 
  sp. 
  

  

  Horizontal, 
  tortuous, 
  and 
  undulating 
  burrows 
  or 
  tracks 
  which 
  

   are 
  simple, 
  rounded 
  furrows 
  of 
  about 
  equal 
  width 
  throughout 
  

   their 
  length. 
  One 
  undulating 
  track 
  is 
  26 
  cm 
  in 
  length 
  and 
  

   4 
  mm 
  in 
  breadth; 
  while 
  some 
  of 
  the 
  very 
  tortuous 
  ones 
  are 
  con- 
  

   siderably 
  longer, 
  as 
  for 
  example 
  one 
  is 
  59 
  cm 
  and 
  5 
  mm 
  in 
  

   breadth. 
  The 
  greater 
  part 
  of 
  the 
  burrows 
  is 
  not 
  filled 
  and 
  is 
  

   smooth. 
  In 
  the 
  better 
  preserved 
  portions 
  of 
  some 
  of 
  the 
  trails, 
  

   however, 
  are 
  somewhat 
  imperfect 
  transverse 
  parallel 
  furrows 
  ajad 
  

   ridges, 
  one 
  specimen 
  having 
  18 
  in 
  the 
  space 
  of 
  1 
  cm. 
  The 
  ridges 
  

   are 
  broader 
  than 
  the 
  furrows, 
  varying 
  from 
  one 
  half 
  to 
  three 
  

   fourths 
  of 
  a 
  mm 
  in 
  width. 
  These 
  furrows 
  and 
  ridges 
  apparently 
  

   represent 
  the 
  segments 
  of 
  the 
  worm. 
  Other 
  portions 
  of 
  the 
  bur- 
  

   rows 
  are 
  filled 
  with 
  cylinders 
  of 
  arenaceous 
  materia), 
  not 
  

   especially 
  different 
  from 
  the 
  matrix, 
  which 
  have 
  a 
  smooth 
  surface 
  

   and 
  show 
  no 
  structure. 
  This 
  filling 
  is 
  probably 
  the 
  sand 
  that 
  was 
  

   passed 
  through 
  the 
  alimentary 
  canal 
  of 
  the 
  worm, 
  although 
  it 
  

   is 
  possible 
  that 
  they 
  are 
  simply 
  casts 
  of 
  trails 
  as 
  have 
  been 
  de- 
  

   scribed 
  by 
  Nathorst. 
  As 
  far 
  as 
  noted 
  these 
  burrows 
  were 
  all 
  in 
  

   the 
  lamination 
  planes 
  of 
  flagstone 
  strata. 
  

  

  These 
  tracks 
  somewhat 
  resemble 
  Gyrichnites 
  gaspensis 
  White- 
  

   aves 
  a 
  from 
  the 
  Lower 
  Devonian 
  (Gaspe' 
  sandstones) 
  of 
  Gasp£ 
  Bay, 
  

   Quebec, 
  but 
  they 
  are 
  much 
  smaller 
  and 
  not 
  marked 
  by 
  the 
  con- 
  

   spicuous 
  grooves 
  of 
  that 
  species. 
  

  

  A 
  specimen 
  was 
  submitted 
  to 
  Prof. 
  Whiteaves 
  who 
  wrote 
  as 
  

   follows: 
  "Your 
  specimen 
  shows 
  parts 
  of 
  the 
  arenaceous 
  filling 
  

   of 
  the 
  burrow 
  or 
  mold, 
  if 
  it 
  is 
  an 
  annelid 
  track, 
  and 
  clearly 
  differs 
  

   from 
  the 
  Gaspe" 
  species 
  of 
  Gyrichnites, 
  as 
  you 
  say, 
  by 
  its 
  much 
  

   smaller 
  size. 
  In 
  your 
  specimen, 
  also, 
  there 
  seems 
  to 
  be 
  somewhat 
  

   greater 
  rigidity, 
  and 
  a 
  closer 
  disposition 
  of 
  the 
  transverse 
  annu- 
  

   lations. 
  

  

  It 
  is 
  not 
  at 
  all 
  easy 
  to 
  make 
  up 
  one's 
  mind 
  as 
  to 
  whether 
  your 
  

   tracks 
  should 
  be 
  regarded 
  as 
  referable 
  to 
  Planolites 
  or 
  to 
  Gyrich- 
  

   nites. 
  For, 
  although 
  the 
  convex 
  filling 
  of 
  your 
  specimen 
  is 
  no 
  

  

  a 
  Trans, 
  roy. 
  soc. 
  Canada, 
  sec. 
  IV, 
  1882, 
  p. 
  109, 
  pi's 
  XI, 
  XII. 
  

  

  