﻿362 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  surface 
  a 
  pronounced 
  longitudinal 
  crest, 
  much 
  thickened 
  and 
  con- 
  

   siderably 
  produced 
  into 
  the 
  matrix 
  at 
  its 
  anterior 
  extremity. 
  

   The 
  general 
  form 
  of 
  the 
  entire 
  shield 
  taken 
  in 
  connection 
  with 
  

   the 
  presence 
  of 
  the 
  median 
  crest 
  would 
  indicate 
  that 
  this 
  is 
  a 
  

   dor 
  so-median 
  plate, 
  in 
  which 
  case 
  its 
  position 
  as 
  represented 
  upon 
  

   Plate 
  I, 
  figure 
  2, 
  is 
  reversed. 
  I 
  am 
  unable 
  to 
  give 
  it 
  any 
  other 
  

   construction 
  or 
  to 
  explain 
  the 
  significance 
  of 
  its 
  evident 
  division 
  

  

  into 
  three 
  parts. 
  

  

  Nautilus 
  Hyatti, 
  Hall. 
  

  

  Palaeontology 
  of 
  New 
  York, 
  vol. 
  v, 
  pt. 
  2 
  (vol. 
  vii, 
  Suppl. 
  p. 
  37, 
  pi. 
  126, 
  fig. 
  1). 
  

   The 
  original 
  of 
  this 
  species 
  was 
  described 
  from 
  the 
  Hamilton 
  

   rocks 
  of 
  Cumberland, 
  Maryland, 
  and 
  has 
  not 
  before 
  been 
  else- 
  

   where 
  recognized. 
  A 
  portion 
  of 
  a 
  body 
  whorl 
  from 
  the 
  Hamilton 
  

   shales 
  at 
  404 
  feet 
  in 
  the 
  Shaft 
  bears 
  similar 
  surface 
  markings 
  to 
  

   N. 
  Hyatti, 
  that 
  is, 
  fine, 
  sharply 
  elevated 
  and 
  distant 
  raised 
  revolv- 
  

   ing 
  lines 
  crossed 
  by 
  frequent 
  concentric 
  lines 
  which 
  become 
  

   obsolete 
  near 
  the 
  aperture 
  of 
  the 
  shtll. 
  

  

  Orthoceras 
  Geneva, 
  sp. 
  nov. 
  

  

  Plate 
  II, 
  figs. 
  5-7. 
  

   This 
  is 
  a 
  fragment 
  from 
  the 
  Corniferous 
  limestone 
  in 
  the 
  

   northern 
  part 
  of 
  G-eneva 
  township, 
  which 
  seems 
  to 
  indicate 
  a 
  new 
  

   representative 
  of 
  the 
  annul 
  ated 
  longitudinally 
  striated 
  orthoce- 
  

   rata. 
  The 
  specimen 
  has 
  been 
  compressed 
  and 
  this 
  has 
  given 
  the 
  

   annulations 
  an 
  unnatural 
  obliquity. 
  There 
  are 
  five 
  of 
  these 
  pre- 
  

   served 
  ; 
  they 
  are 
  broad, 
  low, 
  rounded 
  and 
  with 
  shallow 
  inter- 
  

   spaces, 
  and 
  both 
  annulations 
  and 
  furrows 
  are 
  crossed 
  by 
  longitu- 
  

   dinal 
  striae 
  which 
  are 
  rounded, 
  threadlike 
  and 
  of 
  equal 
  size. 
  

   Concentric 
  striae 
  are 
  exceedingly 
  obscure. 
  The 
  character 
  of 
  this 
  

   surface 
  ornamentation 
  is 
  unlike 
  that 
  in 
  the 
  common 
  annulated 
  

   species 
  of 
  this 
  fauna, 
  0. 
  Thoas, 
  Hall, 
  where 
  the 
  longitudial 
  striae 
  

   alternate 
  in 
  size 
  as 
  they 
  do 
  also 
  in 
  the 
  species 
  0. 
  nunlium, 
  Hall, 
  

   and 
  0. 
  crotalum, 
  Hall, 
  which 
  have 
  also 
  been 
  identified 
  in 
  the 
  

   Corniferous 
  limestone.* 
  

  

  Orthoceras 
  fenestrulatum, 
  sp. 
  nov. 
  

   Plate 
  II, 
  figs. 
  10, 
  11. 
  

   This 
  is 
  a 
  species 
  with 
  a 
  rather 
  broad 
  stout 
  tube, 
  without 
  annu- 
  

   lations, 
  but 
  with 
  a 
  characteristic 
  ornamentation 
  that 
  seems 
  to 
  

  

  ♦Palaeontology 
  of 
  New 
  York, 
  vol. 
  v, 
  pt. 
  2, 
  p. 
  265. 
  

  

  