﻿902 
  Forty-seventh 
  JReport 
  on 
  the 
  State 
  Museum. 
  

  

  sole," 
  is 
  the 
  convincing 
  figure, 
  even 
  more 
  than 
  Hg. 
  1, 
  which 
  

   without 
  supporting 
  evidence, 
  shows 
  clearly 
  the 
  character 
  of 
  

   the 
  fossil. 
  Frequently 
  when 
  a 
  Unitrypa 
  is 
  imbedded 
  in 
  

   a 
  rock 
  the 
  substance 
  of 
  the 
  fossil 
  is 
  dissolved 
  away, 
  leaving 
  a 
  

   mold. 
  When 
  the 
  mold 
  of 
  the 
  summits 
  of 
  the 
  carina 
  and 
  

   connecting 
  processes 
  are 
  broken 
  away 
  it 
  leaves 
  in 
  the 
  rock 
  

   a, 
  structure 
  of 
  which 
  fig. 
  le 
  is 
  an 
  absolutely 
  correct 
  illustration. 
  

   I 
  give 
  here 
  a 
  figure 
  made 
  by 
  myself 
  from 
  Unitrypa 
  lata 
  for 
  

   comparison 
  and 
  to 
  show 
  that 
  Prout's 
  fig. 
  le 
  illustrates 
  the 
  same 
  

   45 
  character. 
  That 
  the 
  fossil 
  or 
  portions 
  of 
  it 
  were 
  

  

  j 
  fgj 
  j^ffgg 
  in 
  this 
  condition 
  is 
  shown 
  by 
  Mr. 
  Prout's 
  own 
  

   <p3SG3w3 
  words 
  : 
  " 
  This 
  interesting 
  fossil 
  was 
  imbedded 
  in 
  

   Iq(3S0 
  a 
  ver 
  y 
  re 
  ^ 
  ra 
  °tory 
  roc 
  k 
  and 
  was 
  so 
  much 
  weather- 
  

   I^jSQ^J 
  w 
  ^rn 
  and 
  the 
  fenestrules 
  so 
  filled 
  with 
  foreign 
  

   i@§BSy 
  matter 
  that 
  it 
  was 
  only 
  after 
  a 
  laborious 
  in- 
  

   1^333 
  vestigation 
  that 
  we 
  were 
  enabled 
  to 
  obtain 
  any- 
  

   OOoS 
  thing 
  approaching 
  a 
  definite 
  view 
  of 
  its 
  organiza- 
  

   •Q^33 
  £I 
  tion. 
  * 
  * 
  * 
  The 
  great 
  diversity 
  of 
  form, 
  

   presented 
  in 
  its 
  complex 
  organization 
  under 
  the 
  

   influence 
  of 
  different 
  degrees 
  of 
  weathering, 
  rendered 
  it 
  often 
  

   very 
  difficult 
  to 
  determine 
  whether 
  we 
  had 
  under 
  our 
  observa- 
  

   tion 
  some 
  modification 
  of 
  normal 
  development 
  or 
  some 
  alteration 
  

   by 
  atmospheric 
  influences." 
  

  

  Figs. 
  1 
  and 
  1 
  e 
  are 
  very 
  good 
  figures 
  indeed 
  of 
  the 
  characters 
  

   on 
  which 
  are 
  founded 
  the 
  genus 
  Unitrj^pa, 
  and 
  I 
  do 
  not 
  see 
  how 
  

   the 
  figures 
  could 
  have 
  been 
  made 
  from 
  any 
  other 
  form. 
  

  

  The 
  first 
  name 
  given 
  to 
  a 
  genus 
  can 
  not, 
  of 
  course, 
  be 
  changed, 
  

   and 
  to 
  the 
  author 
  first 
  describing 
  it 
  the 
  credit 
  should 
  be 
  given, 
  

   but 
  as 
  in 
  this 
  case 
  it 
  is 
  a 
  matter 
  of 
  dispute 
  as 
  to 
  what 
  form 
  was 
  

   described, 
  the 
  name 
  Unitrypa 
  will 
  probably 
  stand 
  unless 
  the 
  

   specimen 
  from 
  which 
  Prout's 
  original 
  description 
  was 
  made 
  can 
  

   be 
  found. 
  In 
  the 
  latter 
  case 
  I 
  have 
  little 
  doubt 
  that 
  it 
  will 
  prove 
  

   to 
  be 
  Unitrypa 
  lata. 
  

  

  UNITRYPA, 
  Hall. 
  

  

  (See 
  Pal. 
  N. 
  Y., 
  vol. 
  VI, 
  pis. 
  li 
  and 
  liii.) 
  

  

  We 
  have 
  seen 
  in 
  a 
  former 
  part 
  of 
  this 
  article 
  how 
  gradual 
  is 
  

  

  the 
  change 
  from 
  those 
  forms 
  of 
  Fenestella 
  having 
  two 
  ranges 
  of 
  

  

  cell 
  apertures 
  separated 
  by 
  a 
  row 
  of 
  nodes 
  along 
  the 
  middle 
  of 
  

  

  the 
  branch 
  to 
  the 
  genus 
  now 
  under 
  discussion. 
  

  

  