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  Twenty-eighth 
  Report 
  ox 
  the 
  State 
  Museum. 
  

   Oethis 
  elegantula 
  Dalman. 
  

  

  Plate 
  21, 
  Figs 
  11-17. 
  

   For 
  Synonymy, 
  see 
  Pal. 
  N. 
  Y., 
  vol. 
  ii, 
  p. 
  252. 
  1852. 
  

  

  Compared 
  with 
  the 
  New 
  York 
  representatives, 
  this 
  species, 
  

   as 
  found 
  at 
  Waldron, 
  is 
  much 
  longer, 
  wider 
  in 
  front, 
  and 
  

   the 
  beak 
  of 
  the 
  ventral 
  valve 
  not 
  so 
  pointed. 
  

  

  STREPTORHYNCHUS 
  King. 
  

   Stkeptoehynchus 
  tenuis. 
  

  

  Plate 
  23, 
  Figs 
  11-13. 
  

  

  Streptorhynchus 
  tenuis 
  Hall. 
  Trans. 
  Alb. 
  Inst., 
  vol. 
  iv, 
  p. 
  210. 
  Abstract 
  p. 
  16; 
  

   May, 
  1863. 
  

  

  Shell 
  large, 
  semicircular 
  or 
  broadly 
  semielliptical, 
  cardinal 
  

   line 
  less 
  than 
  the 
  greatest 
  width 
  of 
  the 
  shell, 
  cardinal 
  extremi- 
  

   ties 
  rounded. 
  Ventral 
  valve 
  slightly 
  concave 
  ; 
  area 
  narrow 
  ; 
  

   beak 
  slightly 
  elevated. 
  Dorsal 
  valve 
  moderately 
  convex, 
  

   umbo 
  not 
  prominent, 
  arcuate 
  near 
  the 
  front 
  margin, 
  and 
  com- 
  

   pressed 
  near 
  the 
  cardinal 
  extremities. 
  

  

  Surface 
  marked 
  by 
  moderately 
  fine, 
  rounded, 
  alternately 
  

   large 
  and 
  small 
  thread-like 
  striae, 
  which 
  are 
  strongly 
  curved 
  

   on 
  the 
  lateral 
  portions 
  of 
  the 
  shell, 
  crossed 
  by 
  very 
  fine 
  con- 
  

   centric 
  striae, 
  giving, 
  under 
  a 
  lens, 
  a 
  beautiful 
  rugose 
  charac- 
  

   ter. 
  Substance 
  of 
  shell 
  very 
  thin. 
  

  

  Length 
  of 
  one 
  specimen, 
  40 
  mm., 
  with 
  a 
  breadth 
  of 
  50 
  mm. 
  

  

  This 
  species 
  differs 
  from 
  any 
  other 
  of 
  the 
  genus 
  known 
  to 
  

   me 
  in 
  rocks 
  of 
  this 
  age, 
  in 
  the 
  rugose 
  surface 
  and 
  rounded 
  

   cardinal 
  extremities 
  ; 
  in 
  this 
  respect 
  it 
  has 
  more 
  the 
  character 
  

   of 
  the 
  carboniferous 
  forms 
  of 
  Streptorhynchus. 
  But 
  few 
  

   individuals 
  of 
  the 
  species 
  have 
  been 
  observed 
  in 
  the 
  extensive 
  

   collections 
  made 
  at 
  the 
  locality. 
  

  

  