﻿170 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  ous 
  on 
  one 
  side 
  only, 
  deeply 
  striated 
  longitudinally 
  on 
  the 
  other; 
  

   quadrangular 
  or 
  subrhomboidal 
  apertures 
  ; 
  branches 
  often 
  thickened 
  

   or 
  clavate, 
  always 
  obtuse. 
  

  

  Found 
  in 
  the 
  upper 
  part 
  of 
  the 
  lower 
  Rochester 
  shale 
  and 
  the 
  

   Bryozoa 
  beds 
  at 
  Niagara. 
  Rare. 
  Also 
  at 
  Lockport 
  (Hall). 
  

  

  Genus 
  fenestella 
  Lonsdale 
  

  

  [Ety.: 
  fenestella, 
  a 
  little 
  window] 
  

  

  (1839. 
  Murchison. 
  Silurian 
  system, 
  p. 
  6yy) 
  

  

  Zoarium 
  consisting 
  of 
  a 
  calcareous 
  branching 
  frond, 
  forming 
  cup- 
  

   shaped 
  or 
  funnel-shaped 
  expansions. 
  The 
  branches 
  fork, 
  and 
  are 
  

   connected 
  by 
  transverse 
  bars 
  or 
  dissepiments, 
  thus 
  inclosing 
  spaces 
  

   or 
  fenestrules. 
  The 
  cell 
  apertures 
  occur 
  only 
  on 
  the 
  inner 
  side 
  of 
  

  

  

  

  Fig. 
  70 
  Fen( 
  Stella 
  elegans 
  with 
  enlargements 
  

  

  the 
  branches. 
  They 
  are 
  surrounded 
  by 
  rims 
  or 
  peristomes 
  and 
  

   are 
  arranged 
  in 
  two 
  parallel 
  rows, 
  while 
  between 
  them 
  occurs 
  a 
  ridge 
  

   (carina) 
  or 
  a 
  row 
  of 
  nodes. 
  

  

  Fenestella 
  elegans 
  Hall 
  (Fig. 
  70) 
  (1852. 
  Pal. 
  N. 
  Y. 
  2:164, 
  pi. 
  

   40D, 
  fig. 
  la-g) 
  

  

  Distinguishing 
  characters. 
  Carina 
  subdued; 
  apertures 
  with 
  their 
  

   longer 
  diameter 
  oblique 
  to 
  the 
  direction 
  of 
  the 
  branches; 
  branches 
  

   slender, 
  frequently 
  bifurcating; 
  thin 
  and 
  slender 
  dissepiments 
  

   scarcely 
  enlarging 
  at 
  the 
  junction 
  with 
  the 
  branches; 
  fenestrules 
  on 
  

  

  