﻿320 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  first 
  its 
  tuberculatum; 
  and 
  second, 
  the 
  fact 
  that 
  the 
  keel 
  ter- 
  

   minated 
  before 
  reaching 
  the 
  posterior 
  margin; 
  and 
  in 
  both 
  these 
  

   respects 
  the 
  plates 
  of 
  D. 
  tuberculatus 
  stand 
  in 
  perfect 
  agreement. 
  

  

  Dinichthys 
  sp. 
  

   The 
  specimen 
  shown 
  in 
  the 
  accompanying 
  figure 
  has 
  the 
  out- 
  

   lines 
  very 
  distinctly 
  preserved, 
  but 
  the 
  substance 
  of 
  the 
  bone 
  has 
  

   been 
  considerably 
  worn 
  or 
  broken 
  away. 
  It 
  obviously 
  represents 
  

   the 
  anterior 
  portion 
  of 
  the 
  mandible 
  belonging 
  to 
  some 
  Arthro- 
  

   dire, 
  for 
  the 
  microscopic 
  structure 
  proves 
  it 
  is 
  not 
  of 
  chimaeroid 
  

   nature. 
  Hence 
  it 
  is 
  most 
  naturally 
  referred 
  to 
  Dinichthys, 
  but 
  

   we 
  are 
  unable 
  to 
  identify 
  it- 
  with 
  any 
  known 
  species. 
  D. 
  minor 
  

   and 
  D. 
  gouldi 
  are 
  the 
  nearest 
  of 
  the 
  Ohio 
  forms 
  with 
  which 
  it 
  can 
  

   be 
  compared, 
  but 
  at 
  best 
  very 
  remotely. 
  Un- 
  

   fortunately, 
  mandibles 
  have 
  not 
  yet 
  been 
  found 
  

   associated 
  with 
  fragments 
  of 
  D. 
  tuberculatus 
  in 
  

   either 
  of 
  the 
  horizons 
  where 
  it 
  occurs, 
  and 
  as 
  

   this 
  is 
  the 
  only 
  contemporaneous 
  species 
  

   known, 
  it 
  is 
  natural 
  to 
  think 
  of 
  it 
  in 
  connec- 
  

   Fi 
  g 
  . 
  i 
  Dinichthys 
  S 
  p. 
  An- 
  tion 
  with 
  the 
  present 
  mandible. 
  The 
  size, 
  also, 
  

  

  terior 
  extremity 
  of 
  man- 
  . 
  

  

  dibie. 
  is 
  not 
  incompatible 
  with 
  the 
  plates 
  of 
  D. 
  tuber- 
  

  

  culatus; 
  but 
  as 
  conjectural 
  associations 
  are 
  for 
  the 
  most 
  part 
  

   unwise, 
  we 
  prefer 
  to 
  leave 
  the 
  species 
  as 
  indeterminable. 
  The 
  

   sinuous 
  posterior 
  cutting 
  edge 
  of 
  the 
  beak 
  and 
  general 
  chimaeroid 
  

   outline 
  are 
  noteworthy 
  features. 
  

  

  Locality; 
  railroad 
  cut 
  one 
  quarter 
  mile 
  north 
  of 
  Franklin 
  

   Station. 
  

  

  Family 
  Holoptychiidae 
  

   Genus 
  holoptychius 
  

  

  The 
  first 
  observer 
  who 
  recognized 
  that 
  Holoptychius 
  and 
  Both- 
  

   riolepis 
  do 
  not 
  belong 
  exclusively 
  to 
  the 
  Catskill 
  fauna, 
  and 
  who 
  

   found 
  their 
  remains 
  in 
  New 
  York 
  state, 
  seems 
  to 
  be 
  E. 
  W. 
  Clay- 
  

   pole. 
  a 
  The 
  species 
  was 
  not 
  determined 
  by 
  him, 
  but 
  may 
  have 
  

  

  a 
  Claypole, 
  E. 
  W. 
  Note 
  on 
  the 
  occurrence 
  of 
  Holoptychius 
  in 
  Bradford 
  county, 
  etc. 
  (Proc. 
  Amer. 
  

   phil. 
  soc, 
  18S3, 
  20:531). 
  

  

  