﻿168 
  Twenty-eighth 
  Repoet 
  on 
  - 
  the 
  State 
  Museum. 
  

  

  This 
  species 
  is 
  very 
  common 
  in 
  the 
  Waldron 
  locality. 
  The 
  

   specimens 
  are 
  larger 
  and 
  in 
  a 
  better 
  state 
  of 
  preservation 
  than 
  

   is 
  usual 
  in 
  the 
  New 
  York 
  localities. 
  

  

  Compared 
  with 
  its 
  European 
  congener, 
  the 
  American 
  form 
  

   is 
  a 
  more 
  robust 
  and 
  larger 
  shell, 
  the 
  surface 
  marked 
  by 
  fewer 
  

   and 
  much 
  stronger 
  plications 
  ; 
  while 
  the 
  transverse 
  strise 
  are 
  

   a 
  little 
  finer 
  and 
  less 
  distant, 
  and 
  the 
  sinus 
  is 
  much 
  deeper 
  

   and 
  more 
  abrupt. 
  

  

  Specimens 
  from 
  Waldron, 
  Indiana, 
  from 
  New 
  York 
  and 
  

   from 
  Dudley, 
  England, 
  have 
  been 
  cut 
  on 
  the 
  dorsal 
  side, 
  and 
  

   all 
  show 
  the 
  crural 
  processes, 
  as 
  in 
  figure 
  1 
  of 
  the 
  accompany- 
  

   ing 
  illustrations. 
  

  

  ANASTROPHIA 
  Hall. 
  

   Anastrophia 
  internascens 
  n. 
  sp. 
  

  

  Plate 
  26, 
  Figs. 
  41-49. 
  

  

  Compare 
  Atrypa 
  interplicata 
  (Sow.) 
  Hall. 
  Pal. 
  N. 
  Y., 
  vol. 
  ii, 
  p. 
  275, 
  pi. 
  57, 
  figs. 
  

   2a-2g. 
  Not 
  Terebratula 
  interplicata 
  (Sow.) 
  Murch. 
  Sil. 
  Syst., 
  p. 
  631, 
  

   pi. 
  13, 
  fig. 
  28. 
  

   " 
  Atrypa 
  brevirostris? 
  (Sow.) 
  Hall. 
  Pal. 
  N. 
  Y., 
  vol. 
  ii, 
  p. 
  278, 
  pi. 
  58, 
  figs. 
  

   la-1/. 
  Not 
  Terebratula 
  brevirostris 
  (Sow.) 
  Murch. 
  Sil. 
  Syflt., 
  p. 
  631, 
  

   pi. 
  13, 
  fig. 
  23. 
  

   " 
  Pentamerus 
  Verneuili 
  Hall. 
  Pal. 
  N. 
  Y., 
  vol. 
  iii, 
  p. 
  260, 
  pi. 
  48, 
  figs, 
  la-ly. 
  

   " 
  Anastrophia 
  Verneuili 
  Hall. 
  Pal. 
  N. 
  Y., 
  vol. 
  iv, 
  p. 
  374. 
  

   " 
  Brachymerus 
  Shaler. 
  Bull. 
  Mus. 
  Comp. 
  Zool, 
  vol. 
  1. 
  1865. 
  

   Anastrophia 
  Verneuili 
  Hall. 
  Doc. 
  Edit. 
  28th 
  Rept. 
  St. 
  Mus. 
  Nat. 
  Hist. 
  Expla- 
  

   nation 
  of 
  pi. 
  26, 
  figs. 
  41^9. 
  1876. 
  

  

  Shell 
  transversely 
  subelliptical, 
  ovoid 
  or 
  subglobose 
  in 
  dif- 
  

   ferent 
  stages 
  of 
  growth, 
  the 
  proportions 
  of 
  length 
  and 
  width 
  

   being 
  sometimes 
  nearly 
  equal. 
  Valves 
  of 
  young 
  specimens 
  

   nearly 
  equal 
  * 
  in 
  convexity 
  ; 
  in 
  older 
  ones 
  the 
  dorsal 
  valve 
  

   becomes 
  the 
  more 
  gibbous. 
  

  

  Ventral 
  valve 
  moderately 
  convex 
  in 
  young 
  or 
  medium- 
  

   sized 
  specimens, 
  and 
  gibbous 
  in 
  the 
  upper 
  part 
  in 
  older 
  speci- 
  

   mens 
  ; 
  the 
  anterior 
  portion 
  depressed 
  and 
  marked 
  by 
  a 
  broad 
  

   undefined 
  sinus 
  ; 
  beak 
  short, 
  acute, 
  closely 
  incurved 
  over 
  the 
  

   umbo 
  of 
  the 
  opposite 
  valve 
  ; 
  area 
  small, 
  short 
  and 
  sharply 
  

   defined. 
  Dorsal 
  valve 
  gibbous, 
  and 
  in 
  old 
  individuals 
  the 
  

   umbo 
  projects 
  beyond 
  the 
  beak 
  of 
  the 
  ventral 
  valve, 
  with 
  the 
  

   apex 
  incurved 
  beneath 
  the 
  beak 
  of 
  the 
  latter 
  ; 
  central 
  portion 
  

   of 
  the 
  valve 
  toward 
  the 
  front 
  more 
  elevated, 
  and 
  sometimes 
  

   presenting 
  a 
  broad 
  undefined 
  mesial 
  fold. 
  

  

  Surface 
  plications 
  abruptly 
  elevated, 
  rounded, 
  angular 
  or 
  

  

  