﻿STRATIGRAPHIC 
  GEOLOGY 
  OF 
  THE 
  EASTERN 
  HELDERBERGS 
  339 
  

  

  PALEONTOLOGY 
  

  

  The 
  data 
  for 
  the 
  preparation 
  of 
  this 
  article 
  have 
  been 
  obtained 
  

   while 
  directing 
  the 
  work 
  of 
  the 
  class 
  of 
  Union 
  college 
  in 
  field 
  

   geology 
  and 
  there 
  has 
  not 
  been 
  the 
  opportunity 
  for 
  a 
  thorough 
  

   collection 
  of 
  the 
  fossils 
  from 
  the 
  different 
  formations. 
  

  

  Tentaculite 
  limestone. 
  This 
  limestone 
  contains 
  but 
  a 
  compara- 
  

   tively 
  small 
  number 
  of 
  species, 
  and 
  only 
  three 
  that 
  occur 
  fre- 
  

   quently. 
  Of 
  these 
  Tentaculites 
  gyracanthus 
  (Eaton) 
  Hall 
  is 
  so 
  

   abundant 
  as 
  to 
  suggest 
  the 
  name 
  for 
  the 
  formation. 
  The 
  follow- 
  

   ing 
  species 
  were 
  obtained 
  : 
  

  

  1 
  Tentaculites 
  gyracanthus 
  (Eaton) 
  Hall 
  (aa) 
  

  

  ' 
  2 
  Spirifer 
  vanuxemi 
  Hall 
  (aa) 
  

  

  3 
  Leperditia 
  alta 
  (Con.) 
  Hall 
  (aa) 
  

  

  1 
  Megambonia 
  aviculoidea 
  Hall 
  (r) 
  

  

  5 
  Modiolopsis 
  (?) 
  duUa 
  Hall 
  (r) 
  

  

  6 
  Cliaetetes 
  (Monotrypella) 
  arbusculus 
  Hall 
  (r) 
  

   Pentamerus 
  limestone. 
  This 
  limestone 
  like 
  the 
  Tentaculite 
  con- 
  

   tains 
  but 
  a 
  small 
  number 
  of 
  species. 
  The 
  Pentamerus 
  galeatus 
  

   Dal., 
  or 
  Sieberella 
  galeata 
  as 
  it 
  is 
  now 
  called 
  by 
  Professors 
  Hall 
  

   and 
  Clarke 
  is 
  fairly 
  abundant 
  and 
  furnished 
  the 
  name 
  for 
  the 
  

   formation. 
  Below 
  is 
  the 
  list 
  of 
  species 
  collected: 
  

  

  1 
  Sieberella 
  galeata 
  (Dal.) 
  H. 
  & 
  C.=Pentamerus 
  galeatus 
  Dal. 
  (a) 
  

  

  2 
  Uncinulus 
  mutabilis 
  (Hall) 
  H. 
  & 
  C. 
  

  

  3 
  Atrypa 
  reticularis 
  (Linn.) 
  Dal. 
  

  

  Shaly 
  limestone. 
  This 
  contains 
  a 
  larger 
  number 
  of 
  species 
  than 
  

   any 
  other 
  formation 
  exposed 
  on 
  Countryman 
  hill 
  and 
  on 
  account 
  

   of 
  the 
  softer 
  nature 
  of 
  the 
  rocks 
  of 
  which 
  it 
  is 
  composed, 
  it 
  is 
  not 
  

   so 
  generally 
  exposed 
  as 
  the 
  other 
  limestones 
  of 
  the 
  Helderberg 
  

   mountains. 
  One 
  of 
  the 
  best 
  localities 
  for 
  collecting 
  yet 
  seen 
  in 
  

   the 
  northern 
  Helderberg 
  region 
  and 
  the 
  one 
  that 
  furnished 
  the 
  

   following 
  species 
  is 
  along 
  the 
  highway 
  below 
  the 
  house 
  of 
  Mr 
  

   K. 
  P. 
  Parrish: 
  

  

  1 
  Stropheodonta 
  (Leptostrophia) 
  becki 
  Hall 
  (c) 
  

  

  2 
  Spirifer 
  perlamellosus 
  Hall 
  (a) 
  

  

  3 
  Leptacna 
  rhombqidalis 
  (Wilckens) 
  H. 
  & 
  C. 
  (a) 
  

  

  