﻿Report 
  of 
  the 
  State 
  Geologist. 
  

  

  905 
  

  

  The 
  description 
  is 
  somewhat 
  vague, 
  but 
  the 
  illustrations 
  show 
  

   it 
  to 
  have 
  precisely 
  the 
  characters 
  of 
  the 
  form 
  described 
  as 
  

   Hemitrypa 
  Mserialis, 
  Lower 
  Helderberg 
  Group, 
  Pal. 
  N. 
  Y., 
  

  

  50 
  

  

  vol. 
  VI, 
  pi. 
  xx 
  ii, 
  figs. 
  13-18, 
  Hemitrypa 
  columellata, 
  Upper 
  

   Helderberg 
  Group, 
  Hemitrypa 
  cribosa, 
  Hamilton 
  Group, 
  etc. 
  

   The 
  characters 
  of 
  the 
  carinse 
  are 
  illustrated 
  in 
  figures 
  50, 
  51. 
  

  

  CYCLOPORINA, 
  nov. 
  gen. 
  

  

  (See 
  Pal. 
  K 
  Y., 
  vol. 
  VI, 
  pi. 
  xlix, 
  figs. 
  12-21, 
  and 
  Ann. 
  Rep.) 
  ' 
  

  

  In 
  the 
  Upper 
  Helderberg 
  and 
  Hamilton 
  groups 
  are 
  certain 
  

   forms 
  of 
  Fenestellidae, 
  the 
  branches 
  of 
  which 
  on 
  the 
  non- 
  

   celluliferous 
  face 
  are 
  more 
  or 
  less 
  regularly 
  zigzag 
  and 
  anasto- 
  

   mosing, 
  and 
  on 
  the 
  celluliferous 
  face 
  have 
  prominent 
  carina^ 
  

   from 
  which 
  proceed 
  lateral 
  semi-circular 
  projections. 
  

  

  These 
  have 
  hitherto 
  been 
  included 
  in 
  the 
  genus 
  Fenestella, 
  but 
  

   I 
  think 
  the 
  peculiarities 
  of 
  their 
  structure 
  are 
  of 
  sufficient 
  import- 
  

   ance 
  to 
  justify 
  placing 
  them 
  in 
  a 
  separate 
  genus. 
  They 
  are 
  

   illustrated 
  in 
  vol. 
  VI, 
  Pal. 
  N. 
  Y., 
  pi. 
  xlix, 
  figs. 
  11-12, 
  and 
  in 
  

   the 
  annual 
  report 
  of 
  the 
  State 
  Geologist 
  for 
  1886, 
  p. 
  55, 
  pi. 
  vii, 
  

   figs. 
  12-15. 
  Two 
  separate 
  species 
  have 
  been 
  included 
  under 
  one 
  

   name 
  in 
  the 
  report, 
  figs. 
  12, 
  15 
  and 
  16, 
  being 
  C. 
  hemicycla, 
  and 
  

   figs. 
  13 
  and 
  14 
  are 
  of 
  another 
  species. 
  Though 
  C. 
  rhomboidea 
  

   was 
  first 
  described, 
  Cycloporina 
  hemicycla 
  is 
  much 
  more 
  

   characteristic, 
  and 
  for 
  that 
  reason 
  I 
  shall 
  make 
  it 
  the 
  type 
  species 
  

   of 
  the 
  genus. 
  It 
  is 
  represented 
  by 
  figure 
  52, 
  

  

  On 
  the 
  non 
  celluliferous 
  face 
  the 
  branches 
  regularly 
  anastomose, 
  

   and 
  that 
  face 
  of 
  the 
  frond 
  resembles 
  very 
  closely 
  the 
  non- 
  cellu- 
  

   liferous 
  face 
  of 
  Reteporina 
  striata 
  and 
  Reteporella 
  retiformis, 
  it 
  

   being 
  almost 
  or 
  quite 
  impossible 
  to 
  distinguish 
  the 
  species 
  by 
  

   that 
  face 
  of 
  the 
  frond. 
  On 
  the 
  celluliferous 
  face 
  the 
  carina 
  is 
  

   thin, 
  not 
  nodose, 
  slightly 
  elevated 
  and 
  having 
  thick 
  semi-circular^ 
  

   lateral 
  projections 
  which 
  extend 
  about 
  half 
  the 
  distance 
  to 
  the 
  

   114 
  

  

  