﻿\ 
  rORB 
  ! 
  mi 
  si;i 
  m 
  

  

  Of 
  these 
  however, 
  I'holidops 
  subtruncata, 
  Modio- 
  

   li 
  modiolaris 
  and 
  Aparchites 
  niinutis- 
  

   d1 
  varietal 
  difi 
  Pholidops 
  sub- 
  

   t 
  p 
  u 
  n 
  c 
  b 
  t 
  a 
  does 
  do! 
  poBsesfi 
  tli* 
  faint 
  median 
  angulation 
  of 
  the 
  

   Lorraine 
  form, 
  and 
  lias 
  besides, 
  been 
  found 
  in 
  the 
  Canadian 
  

   Bton 
  by 
  Ami; 
  M 
  o 
  d 
  i 
  1 
  p 
  S 
  i 
  B 
  in 
  d 
  i 
  o 
  1 
  a 
  r 
  i 
  s 
  has 
  the 
  back 
  

   and 
  base 
  Dearly 
  parallel 
  and 
  thus 
  approaches 
  Ulrich's 
  M. 
  sub- 
  

   ia. 
  identical 
  with 
  one 
  of 
  the 
  Qtica 
  varieties, 
  nien- 
  

   t.v 
  ih'u< 
  author; 
  and 
  also 
  the 
  Aparchites 
  in 
  in 
  u 
  t 
  i 
  s 
  - 
  

   > 
  i 
  in 
  us 
  approaches 
  the 
  Trenton 
  variety 
  by 
  the 
  absence 
  of 
  the 
  

   atra] 
  projecting 
  point. 
  

   The 
  Lorraine 
  element 
  is, 
  hence, 
  by 
  no 
  means, 
  so 
  strongly 
  repre- 
  

   sented 
  in 
  this 
  I'ti.a 
  fauna 
  of 
  Mechanicsville 
  as 
  appears 
  at 
  first 
  

   glance 
  or 
  as 
  it 
  is 
  in 
  the 
  Utica 
  shales 
  of 
  Green 
  Island. 
  This 
  is 
  

   still 
  more 
  emphasized 
  by 
  the 
  absence 
  of 
  Cleidophorus 
  

   p 
  1 
  a 
  n 
  u 
  1 
  a 
  t 
  vrtolites 
  ornatus 
  and 
  Lyrodesma 
  

   pnlchellu 
  m, 
  while, 
  on 
  the 
  other 
  hand, 
  the 
  Trenton 
  element 
  

   Strong 
  that 
  tin* 
  beds 
  almost 
  assume 
  the 
  character 
  of 
  tran- 
  

   Bitional 
  beds 
  between 
  the 
  Trenton 
  and 
  Utica 
  terrani 
  

  

  An 
  important 
  and 
  novel 
  factor 
  in 
  this 
  fauna 
  is 
  the 
  peculiar 
  

   Olimacog 
  r 
  a 
  j» 
  t 
  - 
  u 
  s 
  c 
  a 
  u 
  d 
  a 
  tus. 
  which 
  occurs 
  frequently 
  

   and 
  in 
  large 
  specimens. 
  This 
  striking 
  type 
  of 
  graptolite 
  structure 
  

   was 
  flrst 
  described 
  1».\ 
  Lapworth 
  from 
  the 
  Hartfell 
  shales 
  of 
  Scot- 
  

   land 
  which 
  arc 
  considered 
  homotaxial 
  with 
  the 
  upper 
  Dicello- 
  

   graptufl 
  zone 
  of 
  < 
  fenada, 
  from 
  which 
  the 
  same 
  graptolite 
  has 
  \y 
  

   reported. 
  As 
  it 
  i> 
  restricted 
  to 
  the 
  upper 
  Dicellograptus 
  zone, 
  

   and, 
  therefore, 
  is 
  a 
  valuable 
  index 
  fossil, 
  it* 
  occurrence 
  in 
  the 
  

   es 
  I 
  . 
  shale 
  of 
  Mechanicsville 
  is 
  of 
  significance, 
  indicating 
  

   the 
  pi- 
  sence 
  <»f 
  this 
  zone 
  in 
  the 
  Hudson 
  river 
  region 
  and 
  its 
  prox- 
  

   imity 
  to 
  th.- 
  lowest 
  I'tira. 
  If 
  we 
  add. 
  that 
  also 
  Dawsonia 
  

   mpanulata, 
  found 
  at 
  Mechanicsville, 
  ami 
  Crypto- 
  

   aptns 
  tri 
  <• 
  r 
  n 
  i 
  B, 
  found 
  in 
  similar 
  lower 
  Tjica 
  beds 
  on 
  

  

  Vai 
  3 
  ck 
  island 
  (gee 
  station 
  8) 
  are 
  fossils 
  of 
  the 
  Dicellograptus 
  

  

  zones, 
  and 
  iimi 
  of 
  the 
  Ttica 
  horizon, 
  it 
  ran 
  be 
  concluded 
  with 
  

  

  certainty 
  that 
  the 
  upper 
  Dicellograptns 
  zone, 
  

  

  when 
  present 
  in 
  the 
  EndsOB 
  river 
  valley, 
  directly 
  underlies 
  the 
  

  

  L 
  T 
  ti< 
  rane, 
  that 
  it 
  - 
  omotaxial 
  with 
  the 
  whole 
  or 
  part 
  of 
  the 
  

  

  