﻿980 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum, 
  

  

  Pexidella, 
  Bittner. 
  1890. 
  

   Smooth, 
  biconvex 
  shells, 
  with 
  both 
  valves 
  greatly 
  thickened 
  in 
  

   the 
  umbonal 
  regions. 
  Spiral 
  cones 
  directed 
  laterally; 
  juguin 
  much 
  

   reduced 
  and 
  situated 
  in 
  the 
  umbonal 
  region; 
  saddle 
  scarcely 
  

  

  Figs. 
  328-330. 
  Pexidella 
  Strohmayeri, 
  Suess 
  (sp.). 
  (Bittner.) 
  

  

  developed 
  ; 
  intercalary 
  lamellae 
  narrow 
  and 
  extending 
  for 
  nearly 
  

   the 
  entire 
  length 
  of 
  the 
  principal 
  coils. 
  

  

  Type, 
  Pexidella 
  Strohmayeri, 
  Sue^s 
  (sp.). 
  

  

  Distribution. 
  Triassic. 
  

  

  Diplospirella, 
  Bittner. 
  1890. 
  

   Smooth, 
  biconvex 
  shells 
  with 
  thickened 
  valves. 
  Jugum 
  well 
  

   developed, 
  situated 
  posteriorly; 
  saddle 
  narrow, 
  having 
  the 
  form 
  

   of 
  an 
  oblique 
  stem 
  from 
  the 
  posterior 
  extremity 
  of 
  which 
  are 
  

  

  Figs. 
  331-333. 
  Diplospirella 
  Wissmanni, 
  Munster 
  (sp.). 
  (Bittner.) 
  

  

  given 
  off 
  the 
  intercalary 
  lamellae, 
  which 
  are 
  broad, 
  serrate 
  on 
  

   the 
  outer 
  margin 
  and 
  coextensive 
  with 
  the 
  principal 
  coils. 
  

  

  Type, 
  Diplospirella 
  Wissmanni, 
  Munster 
  (sp.). 
  

  

  Distribution. 
  Triassic. 
  

  

  38 
  

  

  