﻿1128 
  JBORTY-SEVENTH 
  REPORT 
  ON 
  THE 
  8 
  TATE 
  MUSEUM. 
  

  

  Family 
  Thecideid^e, 
  Gray. 
  

  

  Thecidea, 
  Def 
  ranee, 
  1882. 
  

   Lacazella, 
  Munier-Chalmas, 
  1880. 
  

   Thecidiopsis, 
  Munier-Chalmas, 
  1887. 
  

   Thecidella, 
  Munier-Chalmas, 
  1887. 
  

   Eudesella, 
  Munier-Chalmas, 
  1880. 
  

  

  Bactrynium, 
  Emmrich, 
  1885. 
  

  

  Pterophloios, 
  Gumbel, 
  1861 
  . 
  

   Davidsonella, 
  Munier-Chalmas, 
  1880. 
  

   Lyttonia, 
  Waagen,1883. 
  

   Oldhamina, 
  Waagen, 
  1883. 
  

  

  Family 
  Riohthofenidje, 
  Waagen. 
  

   Richthofenia, 
  Waagen, 
  1883. 
  

  

  Family 
  Billingsellidje, 
  Schuchert. 
  

   Billingsella,* 
  Hall, 
  1892. 
  

  

  Family 
  Clitambonitid^e, 
  1ST. 
  H. 
  Winchell 
  and 
  Schuchert. 
  

  

  Hemipronites, 
  Pander, 
  1830. 
  

   Orthisina, 
  d'Orbigny, 
  1847. 
  

   Scenidium, 
  Hall, 
  1860. 
  

  

  Mystrophora, 
  Kayser, 
  1871. 
  

  

  Protorthis, 
  Hall, 
  1892. 
  

   Polytcechia, 
  Hall, 
  1892. 
  

   Clitambonites, 
  Pander, 
  1830. 
  

  

  Pronites, 
  Pander, 
  1830. 
  

  

  Gonambonites, 
  Pander, 
  1830. 
  

  

  Family 
  Stbicexandiniid^e. 
  

   Syntrophia, 
  Hall, 
  1892. 
  | 
  Stricklandinia, 
  Billings, 
  1859. 
  

  

  Family 
  Camabelltd^e. 
  

  

  Camarella, 
  Billings, 
  1859. 
  

   Parastrophia, 
  Hall, 
  1893. 
  

   Anastrophia, 
  Hall, 
  1879. 
  

  

  Brachymerus, 
  Shaler, 
  1865. 
  

   (?) 
  Branconia, 
  Gagel, 
  1890. 
  

   Porambonites, 
  Pander, 
  1830. 
  

  

  Isorhynchus, 
  King, 
  1850. 
  

   Noetlingia, 
  Hall, 
  1892. 
  

   Lycophoria, 
  Lahusen, 
  1885. 
  

   Camarophoria, 
  King, 
  1846. 
  

   Camarophorella, 
  Hall, 
  1893. 
  

  

  

  Conchidium, 
  Linne, 
  1753. 
  

  

  Gypidia, 
  Dalman, 
  1828. 
  

  

  Antirhynchonella, 
  Quenstedt, 
  1871 
  

  

  Zdimir, 
  Barrande, 
  1879. 
  

   Pentamerus, 
  Sowerby, 
  1813. 
  

   Barrandella, 
  Hall, 
  1893. 
  

  

  Family 
  Pentamebidje. 
  

  

  Sieberella, 
  CEhlert, 
  1887. 
  

   Capellinia, 
  Hall, 
  1893. 
  

   Pentamerella, 
  Hall, 
  1867. 
  

   Gypidula, 
  Hall, 
  1867. 
  

   Amphigenia, 
  Hall, 
  1867. 
  

  

  * 
  The 
  genus 
  Billingsella 
  presents, 
  in 
  correspondence 
  with 
  its 
  early 
  geological 
  age, 
  an 
  ele- 
  

   mentary 
  structural 
  aspect 
  indicating 
  that 
  it 
  may 
  have 
  served 
  as 
  a 
  point 
  of 
  departure 
  for 
  the 
  

   Orthidas 
  and 
  Strophomenidse, 
  

  

  186 
  

  

  