﻿44 
  A. 
  F. 
  Foerste 
  — 
  Relations 
  of 
  the 
  

  

  in 
  the 
  rostral 
  extension 
  of 
  the 
  median 
  lobe. 
  There 
  is 
  no 
  

   generic 
  relationship, 
  and 
  the 
  European 
  species 
  appar- 
  

   ently 
  is 
  of 
  pre-Chazyan 
  age. 
  

  

  Acrolichas 
  trentonensis, 
  PI. 
  I, 
  figs. 
  3 
  A, 
  B 
  ; 
  PL 
  III, 
  figs. 
  

   4A-D. 
  The 
  type 
  of 
  this 
  species 
  was 
  fonnd 
  in 
  the 
  Tren- 
  

   ton, 
  at 
  Carlisle, 
  Pennsylvania, 
  bnt 
  the 
  species 
  occurs 
  also 
  

   in 
  the 
  Trenton 
  of 
  New 
  Jersey. 
  The 
  cranidium 
  figured 
  on 
  

   Plate 
  I 
  was 
  obtained 
  from 
  the 
  Trenton 
  near 
  Biff's 
  Pond, 
  

   and 
  forms 
  No. 
  10371 
  in 
  Walker 
  Museum, 
  at 
  Chicago 
  Uni- 
  

   versity. 
  The 
  fragment 
  of 
  a 
  pygidium 
  figured 
  by 
  Hall 
  

   (Pal. 
  New 
  York, 
  1, 
  pi. 
  64, 
  fig. 
  lb, 
  1847) 
  from 
  the 
  Trenton 
  

   at 
  Carlisle, 
  Pennsylvania, 
  has 
  been 
  redrawn 
  in 
  outline 
  

   (PL 
  III, 
  fig. 
  4C) 
  with 
  the 
  margin 
  restored. 
  As 
  already 
  

   noted, 
  the 
  species 
  is 
  not 
  known 
  to 
  range 
  north 
  of 
  New 
  

   York. 
  It 
  is 
  incorrectly 
  listed 
  from 
  Missouri. 
  It 
  is 
  

   unknown 
  in 
  the 
  Mississippi 
  valley. 
  

  

  Acrolichas 
  comutus, 
  PL 
  I, 
  fig. 
  5; 
  pi. 
  Ill, 
  figs. 
  5 
  A, 
  B, 
  

   C. 
  This 
  is 
  a 
  very 
  interesting 
  specimen, 
  notwithstand- 
  

   ing 
  its 
  imperfect 
  preservation. 
  It 
  is 
  from 
  the 
  Trenton, 
  

   at 
  Trenton 
  Falls, 
  New 
  York. 
  The 
  cranidium 
  is 
  very 
  

   poorly 
  preserved 
  and 
  in 
  addition 
  appears 
  to 
  have 
  been 
  

   compressed 
  diagonally 
  from 
  the 
  right, 
  so 
  as 
  to 
  expose 
  

   the 
  right 
  side 
  of 
  the 
  glabella 
  fairly 
  well, 
  while 
  the 
  left 
  

   side 
  of 
  the 
  glabella 
  is 
  seen 
  askew. 
  Traces 
  of 
  the 
  surface 
  

   of 
  the 
  free 
  cheek 
  suggest 
  that 
  the 
  genal 
  ends 
  were 
  fal- 
  

   cate, 
  somewhat 
  as 
  in 
  Acrolichas 
  cucullus 
  (PL 
  I, 
  fig. 
  ID). 
  

   It 
  will 
  be 
  noted 
  that 
  in 
  the 
  figure 
  presented 
  on 
  Plate 
  I 
  

   the 
  genal 
  spine 
  on 
  the 
  right 
  is 
  more 
  acute 
  and 
  more 
  

   falcate 
  than 
  that 
  on 
  the 
  left; 
  the 
  former 
  is 
  regarded 
  

   as 
  nearer 
  the 
  fact, 
  although 
  the 
  state 
  of 
  preservation 
  

   is 
  too 
  imperfect 
  for 
  accurate 
  determination. 
  The 
  an- 
  

   terior 
  part 
  of 
  the 
  median 
  lobe 
  projects 
  upward 
  and 
  

   forward 
  (PL 
  III, 
  fig. 
  5 
  C) 
  and 
  is 
  surmounted 
  by 
  a 
  spine 
  

   of 
  unknown 
  length, 
  only 
  the 
  base 
  being 
  preserved. 
  In 
  

   the 
  anterior 
  and 
  upward 
  elongation 
  of 
  the 
  median 
  lobe, 
  

   this 
  species 
  resembles 
  Conolichas 
  schmidti 
  Dames 
  (PL 
  

   IV, 
  fig. 
  9 
  B) 
  from 
  the 
  East 
  Baltic 
  provinces. 
  However, 
  

   there 
  is 
  no 
  generic 
  relationship. 
  The 
  East 
  Baltic 
  species 
  

   comes 
  from 
  a 
  horizon 
  approximately 
  equivalent 
  to 
  the 
  

   Trenton 
  of 
  New 
  York. 
  

  

  Acrolichas 
  conifrons, 
  PL 
  I, 
  figs. 
  4 
  A. 
  B. 
  C. 
  This 
  is 
  

   another 
  interesting 
  species, 
  also 
  from 
  the 
  Trenton, 
  at 
  

   Trenton 
  Falls, 
  New 
  York. 
  Since 
  the 
  original 
  publica- 
  

   tion 
  of 
  the 
  species 
  (Bull. 
  N. 
  Y. 
  St. 
  Museum, 
  No. 
  189, 
  

  

  