﻿2l6 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  4 
  

  

  .V. 
  

  

  ter 
  shale 
  and 
  Lockport 
  limestone 
  at 
  Lockport 
  (Hall), 
  and 
  probably 
  

   also 
  at 
  Niagara. 
  

  

  Orthoceras 
  meduUare 
  Hall 
  (i860. 
  Geol. 
  stir. 
  Wis. 
  Rep't 
  prog. 
  p. 
  4) 
  

   Distinguishing 
  characters. 
  Cylindric, 
  gradually 
  tapering 
  form; 
  

   septa 
  distant 
  nearly 
  half 
  the 
  diameter; 
  large 
  siphuncle, 
  slightly 
  ex- 
  

   panded 
  between 
  septa; 
  strong 
  sharp 
  subequal 
  longitudinal 
  striae, 
  

   with 
  often 
  alternating 
  finer 
  striae; 
  smooth 
  cast. 
  

  

  Found 
  in 
  the 
  Clinton 
  limestone 
  lenses 
  in 
  the 
  Rome, 
  Watertown 
  

  

  and 
  Ogdensburg 
  railroad 
  section 
  

   above 
  Lewiston. 
  Rare. 
  The 
  species 
  

   is 
  normally 
  a 
  western 
  one. 
  

  

  Genus 
  cyrtoceras 
  Goldfuss 
  

  

  [Ety. 
  : 
  -/.upro^, 
  curved; 
  xipa^, 
  horn] 
  

  

  (1837. 
  De 
  la 
  Beche, 
  Handb. 
  d. 
  

   Geogn. 
  bearb. 
  von 
  v. 
  Dechen. 
  p. 
  536) 
  

  

  ,4 
  Shell 
  conic 
  and 
  gently 
  curved, 
  with 
  

  

  / 
  a 
  depressed 
  elliptic 
  to 
  trigonal 
  cross- 
  

   ,f 
  / 
  section, 
  the 
  aperture 
  in 
  old 
  shells 
  con- 
  

  

  tracted 
  to 
  a 
  T-shaped 
  opening; 
  si- 
  

   phuncle 
  large, 
  eccentric. 
  

  

  Cyrtoceras 
  subcancellatum 
  Hall 
  

  

  (Fig. 
  148). 
  Cyrtoceras 
  (?) 
  

  

  • 
  Fig 
  U8 
  Cyrtoceras 
  subcancellatum 
  canccllatum 
  Hall 
  (1852. 
  Pal 
  

  

  N. 
  Y. 
  2:290, 
  pi. 
  61) 
  

  

  Distinguishing 
  characters. 
  Arcuate; 
  transversely 
  oval 
  section; 
  

   transversely 
  striated 
  surface, 
  and 
  faint 
  longitudinal 
  striae 
  ; 
  siphuncle 
  

   submarginal. 
  

  

  Found 
  in 
  the 
  " 
  limestone 
  below 
  the 
  cHf¥ 
  at 
  Niagara 
  Falls 
  " 
  (Hall). 
  

  

  Genus 
  gomphoceras 
  Sowerby 
  

  

  [Ety.: 
  Yo6!J.(po^, 
  a 
  pin, 
  bolt, 
  or 
  club; 
  y.ipo.^, 
  a 
  horn] 
  

  

  (1839. 
  Murchison. 
  Silurian 
  system, 
  p. 
  620) 
  

  

  Shell 
  straight 
  or 
  curved, 
  pear-shaped, 
  greatest 
  diameter 
  in 
  front 
  

   of 
  the 
  middle; 
  cross-section 
  circular; 
  mouth 
  contracted, 
  opennig 
  by 
  

   a 
  T-shaped 
  aperture 
  ; 
  siphuncle 
  central 
  or 
  eccentric, 
  subcylindric 
  or 
  

   expanding 
  between 
  the 
  septa 
  (moniliform). 
  

  

  