﻿Report 
  of 
  tee 
  State 
  Geologist. 
  977 
  

  

  Tetractinella, 
  Bittner. 
  1890. 
  

   Synonym; 
  Plicigera, 
  Bittner, 
  1890. 
  

   Shells 
  with 
  four 
  corresponding 
  ribs 
  on 
  each 
  valve; 
  spiral 
  cones 
  

   directed 
  laterally 
  ; 
  jugal 
  branches 
  erect, 
  uniting 
  in 
  an 
  elongate 
  

  

  Figs. 
  316-318 
  — 
  Tetractinella 
  trigonella, 
  Schlotheim 
  (sp 
  ) 
  (Bittner). 
  

  

  narrow 
  and 
  nearly 
  vertical 
  saddle 
  from 
  the 
  posterior 
  extremity 
  

   of 
  which 
  short 
  intercalary 
  lamellae 
  are 
  given 
  off. 
  

  

  Type. 
  Tetractinella 
  trigonella, 
  Schlotheim 
  (sp.). 
  

  

  Distribution. 
  Triassic. 
  

  

  Subgenus 
  Pentactinella, 
  Bittner. 
  1890. 
  

  

  Figs. 
  319, 
  310 
  —Pentactinella 
  quinquecostata; 
  Mtinster 
  Op.). 
  (Bittner 
  ) 
  

  

  Shells 
  with 
  five 
  corresponding 
  ribs 
  on 
  each 
  valve. 
  Interior 
  as 
  

   in 
  Tetractinella. 
  

  

  (Type, 
  Pentactinella 
  quinquecostata, 
  Miinster 
  (sp.). 
  Triassic.) 
  

  

  Subgenus 
  Anomactinella, 
  Bittner. 
  1 
  890. 
  

  

  Figs. 
  321, 
  322 
  —Anomactinella 
  flexuosa, 
  Mtinster 
  (sp.). 
  (Bittner.) 
  

  

  Shells 
  with 
  a 
  number 
  of 
  ribs 
  sharply 
  developed 
  toward 
  the 
  

   margins 
  . 
  Interior 
  probably 
  as 
  in 
  Tetractinella 
  . 
  

  

  (Type, 
  Anomactinella 
  flexuosa, 
  Mtinster 
  (sp.). 
  Triassic.) 
  

   123 
  35 
  

  

  