﻿1080 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  (Type, 
  Aulacothyris 
  resupinata, 
  Sowerbv 
  (sp.). 
  Trias 
  — 
  Cre- 
  

   taceous.) 
  

  

  Figs. 
  583-586. 
  Aulacothyris 
  resupinata, 
  Sowerby 
  (sp.). 
  (Davidson.) 
  

  

  Subgenus 
  Epicyrta, 
  Deslongchamps. 
  1884. 
  

  

  Smooth 
  naviculoid 
  shells 
  with 
  broad 
  median 
  sinus 
  on 
  pedicle- 
  

   valve 
  and 
  corresponding 
  elevation 
  on 
  the 
  brachial 
  valve. 
  

  

  Figs. 
  587, 
  588. 
  Epic 
  rta 
  Eugenii, 
  von 
  Buch 
  (sp.). 
  (Quenstedt.) 
  

  

  (Type, 
  Epicyrta 
  Eugenii, 
  von 
  Buch 
  (sp.). 
  Jurassic.) 
  

  

  Subgenus 
  Plesiothyris, 
  Douville. 
  1880. 
  

  

  Shells 
  biconvex, 
  brachial 
  valve 
  biplicate. 
  Dental 
  plates 
  and 
  

   dorsal 
  median 
  septum 
  present. 
  Loop 
  long. 
  

  

  (Type, 
  Plesiothyris 
  Verneuilii, 
  Deslongchamps 
  (sp.). 
  Jurassic.) 
  

  

  138 
  

  

  