﻿2GO 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  ones 
  on 
  either 
  side; 
  linear 
  interspaces; 
  sharply 
  defined 
  fold 
  of 
  

   brachial 
  valve, 
  with 
  plications 
  almost 
  obsolete. 
  

  

  Found 
  only 
  in 
  the 
  Manlius 
  limestone 
  of 
  North 
  Buffalo 
  and 
  Will- 
  

   iamsville. 
  Not 
  common. 
  

  

  Spirifer 
  (Delthyris) 
  sulcatus 
  Hall 
  (Fig. 
  120) 
  (1852. 
  Pal. 
  N. 
  Y. 
  

  

  2:261, 
  pi. 
  54) 
  

  

  Distinguishing 
  characters. 
  Near- 
  

   ly 
  equal 
  valves; 
  deep 
  m.esial 
  

   sinus 
  ; 
  four 
  or 
  more 
  plications 
  on 
  

   either 
  side, 
  with 
  wide 
  inter- 
  

   spaces; 
  fine 
  radiating 
  striae 
  

   crossing 
  plications 
  and 
  inter- 
  

   Pig. 
  120 
  spirifer 
  (Deithyris) 
  suicatus 
  with 
  striae 
  spaces 
  ; 
  very 
  coarse, 
  lamellose, 
  

   enlarged 
  subcqually 
  spaccd 
  concentric 
  

  

  growth 
  lines 
  which 
  interrupt 
  the 
  radiating 
  striae. 
  

  

  Found 
  rarely 
  in 
  the 
  Clinton 
  lenses 
  and 
  the 
  lower 
  Rochester 
  shale; 
  

   more 
  common 
  in 
  the 
  Bryozoa 
  beds 
  at 
  Niagara. 
  Also 
  at 
  Lockport 
  

   and 
  elsewhere 
  (Hall). 
  

  

  Genus 
  homoeospira 
  Hall 
  & 
  Clarke 
  

  

  [Ety. 
  : 
  6/j.()t(>?, 
  like; 
  ff-eipa, 
  spire] 
  

  

  (1893. 
  Pal. 
  N. 
  Y. 
  V. 
  8, 
  pt 
  2, 
  p. 
  112) 
  

  

  Shell 
  rostrate, 
  radially 
  plicate, 
  and 
  with 
  a 
  short 
  curved 
  hinge 
  line; 
  

   apex 
  truncated 
  by 
  a 
  circular 
  pedicle 
  opening. 
  Spirals 
  spiriferoid, 
  

   with 
  from 
  six 
  to 
  nine 
  volutions 
  and 
  a 
  V-shaped 
  jugum. 
  A 
  linear 
  

   cardinal 
  process 
  separates 
  the 
  crural 
  plates. 
  

  

  Homoeospira 
  apriniformis 
  Hall 
  (Fig. 
  121). 
  

   Atrypa 
  aprinis 
  Hall 
  (1852. 
  Pal. 
  N. 
  Y. 
  

  

  2:200, 
  pi. 
  57) 
  Fig. 
  121 
  Homoeospira 
  apriai- 
  

  

  Distiiiguishing 
  characters. 
  Small, 
  roundish, 
  

   oval, 
  scarcely 
  longer 
  than 
  wide; 
  nearly 
  equally 
  convex 
  valves; 
  non- 
  

   sinuate 
  front, 
  numerous 
  simple 
  rounded 
  plications; 
  fine 
  concentric 
  

   striae. 
  

  

  Found 
  in 
  the 
  Rochester 
  shale 
  at 
  Lockport 
  (Hall). 
  Probably 
  also 
  

   at 
  Niagara. 
  

  

  