﻿REPORT 
  OF 
  THE 
  DIRECTOR 
  I9T2 
  1 
  39 
  

  

  The 
  species 
  under 
  present 
  consideration 
  conforms 
  in 
  these 
  

   structures 
  to 
  other 
  American 
  Homalonoti 
  and 
  is 
  to 
  be 
  directly 
  

   compared 
  with 
  H. 
  vanuxemi 
  of 
  the 
  New 
  York 
  Helderberg 
  

   and 
  H. 
  major 
  of 
  the 
  New 
  York 
  Oriskany, 
  accounts 
  of 
  which 
  

   are 
  to 
  be 
  found 
  in 
  Palaeontology 
  of 
  New 
  York, 
  volume 
  7. 
  This 
  

   resemblance 
  is 
  not 
  unexpected 
  in 
  view 
  of 
  the 
  many 
  other 
  affili- 
  

   ations 
  of 
  the 
  Perce 
  and 
  Grande 
  Greve 
  Lower 
  Devonic 
  faunas 
  

   with 
  those 
  of 
  New 
  York. 
  The 
  Perce 
  Homalonotus 
  is 
  represented 
  

   by 
  specimens 
  which 
  indicate 
  its 
  large 
  size. 
  The 
  largest 
  known 
  

   example 
  of 
  H. 
  vanuxemi 
  is 
  a 
  broken 
  individual 
  from 
  Ron- 
  

   dout, 
  N. 
  Y., 
  and 
  indicates 
  an 
  animal 
  280 
  mm 
  in 
  length, 
  which 
  is 
  

   almost 
  exactly 
  the 
  proportions 
  of 
  the 
  Perce 
  species. 
  But 
  even 
  

   so 
  large, 
  these 
  specimens 
  fall 
  far 
  below 
  the 
  dimensions 
  of 
  

   H. 
  major, 
  the 
  largest 
  of 
  all 
  members 
  of 
  the 
  genus. 
  Yet 
  there 
  

   are, 
  between 
  these 
  two 
  species, 
  few 
  differences 
  except 
  dimen- 
  

   sions, 
  habitat 
  and 
  geologic 
  horizon. 
  In 
  structure 
  they 
  are 
  

   closely 
  alike, 
  the 
  smaller 
  H. 
  vanuxemi 
  occurring 
  in 
  the 
  

   Helderberg 
  limestones 
  and 
  lime 
  shales 
  and 
  H 
  . 
  major 
  in 
  the 
  

   Oriskany 
  silicious 
  limestones. 
  The 
  Perce 
  species 
  is 
  rather 
  bet- 
  

   ter 
  preserved 
  and 
  now 
  better 
  known 
  in 
  its 
  details 
  than 
  either 
  of 
  

   the 
  New 
  York 
  species 
  mentioned, 
  but 
  its 
  designation 
  must 
  show 
  

   its 
  affinity 
  to 
  them 
  even 
  at 
  the 
  cost 
  of 
  a 
  multiplex 
  name. 
  I 
  there- 
  

   fore 
  venture 
  so 
  far 
  as 
  to 
  express 
  this 
  relationship 
  by 
  the 
  desig- 
  

   nation 
  Homalonotus 
  ( 
  v.-m. 
  ) 
  perceensis. 
  

  

  The 
  structure 
  of 
  the 
  parts 
  is 
  indicated 
  in 
  the 
  drawings 
  which 
  

   show 
  the 
  pygidium 
  in 
  normal 
  convexity 
  and 
  entire, 
  six 
  of 
  the 
  

   eleven 
  thoracic 
  segments 
  (all 
  are 
  preserved 
  on 
  a 
  second 
  but 
  

   somewhat 
  worn 
  example), 
  the 
  head, 
  partly 
  worn 
  away 
  and 
  

   the 
  hypostoma. 
  The 
  obscurity 
  of 
  segmentation 
  of 
  the 
  pygidium 
  

   is 
  characteristic 
  and 
  differential 
  from 
  other 
  Devonic 
  species, 
  

   especially 
  the 
  common 
  middle 
  Devonic 
  H 
  . 
  d 
  e 
  k 
  a 
  y 
  i 
  . 
  The 
  cephalon 
  

   of 
  H. 
  vanuxemi-major 
  has 
  not 
  been 
  well 
  made 
  out 
  and 
  

   the 
  hypostoma 
  of 
  this 
  type 
  is 
  now 
  seen 
  for 
  the 
  first 
  time, 
  

   both 
  of 
  the 
  Perce 
  specimens 
  showing 
  this 
  organ. 
  

  

  The 
  author 
  has 
  shown 
  the 
  presence 
  of 
  H. 
  vanuxemi 
  in 
  

   the 
  Lower 
  Devonic 
  Moose 
  River 
  formation 
  of 
  Maine 
  at 
  Mata- 
  

   gamon 
  and 
  Moosehead 
  lakes. 
  1 
  Until 
  now 
  no 
  representative 
  of 
  the 
  

   genus 
  has 
  been 
  known 
  from 
  points 
  farther 
  north. 
  

  

  1 
  N. 
  Y. 
  State 
  Mus. 
  Mem. 
  9, 
  v. 
  2, 
  p. 
  67. 
  

  

  