﻿I 
  

  

  NIAGARA 
  FALLS 
  AND 
  VICINITY 
  137 
  

  

  ance, 
  somewhat 
  resennbling 
  the 
  convolutions 
  of 
  the 
  intestine; 
  those 
  

   of 
  the 
  last 
  cycles 
  short; 
  all 
  with 
  papillate 
  elevations 
  or 
  carinae 
  on 
  

   the 
  sides, 
  giving 
  in 
  section 
  a 
  crenulate 
  or 
  echinate 
  appearance. 
  Dis- 
  

   sepiments 
  present. 
  Epitheca 
  well 
  developed. 
  

  

  Enterolasma 
  caliculus 
  (Hall) 
  (Fig. 
  29) 
  S 
  t 
  r 
  e 
  p 
  t 
  e 
  1 
  a 
  s 
  m 
  a 
  

   caliculus 
  Hall 
  (1852. 
  Pal. 
  N. 
  Y. 
  2:111, 
  pi. 
  32) 
  

  

  Distinguishing 
  characters. 
  Turbinate, 
  oblique 
  or 
  curved, 
  more 
  

   or 
  less 
  rapidly 
  expanding 
  form; 
  

   moderately 
  deep 
  cup; 
  septa 
  20 
  to 
  

   50, 
  separated 
  by 
  a 
  space 
  of 
  twice 
  

   their 
  width; 
  well 
  marked 
  costal 
  

  

  grooves 
  which 
  lie 
  opposite 
  both 
  m-lMf 
  NgpT 
  

  

  long 
  and 
  short 
  septa; 
  relatively 
  thin 
  

  

  1 
  ,1 
  . 
  , 
  1 
  Fig. 
  29 
  Enterolasma 
  caliculus 
  

  

  and 
  smooth 
  epitheca. 
  

  

  Found 
  rarely 
  in 
  the 
  upper 
  Clinton 
  beds, 
  and 
  abundantly 
  in 
  the 
  

   lenses 
  of 
  limestone 
  in 
  the 
  Clinton, 
  the 
  lower 
  part 
  of 
  the 
  Rochester 
  

   shales 
  and 
  the 
  Bryozoan 
  beds 
  of 
  these 
  shales. 
  Also 
  in 
  the 
  same 
  

   shales 
  at 
  Lockport 
  and 
  farther 
  east. 
  

  

  Genus 
  zaphrentis 
  Rafinesque 
  

  

  [Ety. 
  : 
  C«, 
  many; 
  (fprjv, 
  diaphragm] 
  

  

  (1820. 
  Ann. 
  des 
  sci. 
  phys. 
  Brux. 
  5:234) 
  

  

  Corallum 
  simple, 
  conic 
  or 
  turbinate, 
  or 
  conico-cyhndric, 
  with 
  a 
  

   deep 
  calyx, 
  and 
  well 
  developed 
  septa, 
  the 
  primary 
  ones 
  reaching 
  to 
  

   the 
  center. 
  Dissepiments 
  and 
  tabulae 
  occur, 
  the 
  latter 
  usually 
  well 
  

   developed. 
  A 
  deep 
  fossula 
  marks 
  the 
  abortion 
  of 
  one 
  of 
  the 
  four 
  

   primary 
  septa. 
  Costae 
  and 
  a 
  thin 
  epitheca 
  occur. 
  

  

  Zaphrentis 
  turbinata 
  (Hall) 
  (Fig. 
  30). 
  Polydilasma 
  tur- 
  

   binatum 
  Hah 
  (1852. 
  Pa/. 
  A^. 
  F. 
  2:112, 
  pi. 
  32) 
  

  

  Distinguishing 
  characters. 
  Form 
  variable, 
  usually 
  short 
  and 
  tur- 
  

   binate 
  ; 
  calyx 
  gradually 
  deepening 
  from 
  margin 
  halfway 
  to 
  the 
  center 
  

   and 
  then 
  abruptly 
  descending, 
  almost 
  vertically 
  to 
  a 
  moderate 
  depth 
  ; 
  

   alternate 
  septa 
  terminating 
  at 
  point 
  of 
  sudden 
  deepening 
  of 
  calyx, 
  

   others 
  reaching 
  to 
  center; 
  dissepiments 
  sHghtly 
  developed. 
  

  

  Found 
  in 
  the 
  Lockport 
  limestone 
  at 
  Niagara(?) 
  and 
  Lockport, 
  

   where 
  it 
  occurs 
  a 
  few 
  feet 
  above 
  the 
  shale. 
  

  

  