﻿92 
  Twenty-eighth 
  Kepobt 
  on 
  the 
  State 
  Museum. 
  

  

  to 
  the 
  sides 
  of 
  the 
  visceral 
  cavity, 
  just 
  above 
  the 
  axial 
  append- 
  

   ages 
  ; 
  they 
  are 
  longer 
  than 
  those 
  of 
  Ceraurus 
  pleurexan- 
  

   themus, 
  and 
  somewhat 
  modified. 
  In 
  that 
  species, 
  they 
  are 
  

   attached 
  beneath 
  the 
  pleural 
  lobes 
  and 
  curve 
  forward 
  and 
  

   downward, 
  while 
  in 
  Calymene 
  senaria 
  they 
  extend 
  outwardly 
  

   beneath 
  the 
  pleural 
  lobe, 
  following 
  its 
  curvature 
  nearly 
  to 
  the 
  

   extremity 
  of 
  the 
  pleurae. 
  It 
  is 
  on 
  the 
  evidence 
  furnished 
  by 
  

   three 
  sections, 
  that 
  the 
  conclusion 
  is 
  reached, 
  that 
  a 
  second 
  

   branchial 
  appendage 
  was 
  attached 
  on 
  each 
  side 
  just 
  below 
  the 
  

   other. 
  A 
  section 
  of 
  a 
  partially 
  coiled 
  specimen 
  shows 
  fine 
  

   branchial 
  appendages 
  on 
  each 
  side, 
  brought 
  into 
  this 
  position 
  

   by 
  the 
  rolling 
  up 
  of 
  the 
  animal. 
  These 
  sections 
  show 
  that 
  the 
  

   axial 
  are 
  but 
  one-third 
  the 
  length 
  of 
  the 
  branchial 
  appendages. 
  

   The 
  perfect 
  state 
  of 
  preservation 
  of 
  the 
  delicate 
  branchial 
  

   appendages 
  and 
  the 
  ventral 
  membrane 
  precludes 
  the 
  idea 
  of 
  

   the 
  destruction 
  of 
  any 
  thing 
  of 
  a 
  stronger 
  texture 
  than 
  fleshy 
  

   swimming 
  lobes 
  attached 
  to 
  the 
  axial 
  appendages. 
  The 
  axial 
  

   appendages 
  could 
  not 
  have 
  reached 
  to 
  the 
  surface 
  upon 
  which 
  

   the 
  edges 
  of 
  the 
  pleurae 
  rested, 
  which 
  negatives 
  the 
  view 
  of 
  

   their 
  being 
  in 
  any 
  way 
  ambulatory, 
  in 
  case 
  the 
  non 
  -presence 
  

   of 
  articulations, 
  in 
  the 
  appendages, 
  should 
  be 
  called 
  in 
  ques- 
  

   tion. 
  The 
  axial 
  appendages 
  of 
  each 
  series 
  approximate 
  each 
  

   other 
  near 
  the 
  posterior 
  end 
  of 
  the 
  hypostoma. 
  What 
  may 
  

   be 
  called 
  oral 
  appendages 
  extend 
  out 
  between 
  the 
  hypostoma 
  

   and 
  the 
  dorsal 
  shell, 
  or 
  else 
  they 
  were 
  articulated 
  to 
  a 
  mem- 
  

   brane 
  connecting 
  the 
  hypostoma 
  and 
  dorsal 
  shell 
  of 
  the 
  head. 
  

  

  Of 
  over 
  two 
  hundred 
  trilobites, 
  which 
  have 
  furnished 
  evi- 
  

   dence 
  of 
  appendages, 
  etc., 
  all 
  were 
  resting 
  with 
  the 
  dorsal 
  

   surface 
  downward. 
  

  

  N. 
  Y. 
  State 
  Museum 
  of 
  Nat. 
  Hist., 
  

   December, 
  1876. 
  

  

  