﻿186 
  Twenty-eighth 
  Report 
  ox 
  the 
  State 
  Museum. 
  

  

  CEUSTACEA. 
  

  

  LEPERDITIA 
  Roualt 
  

   Leperditia 
  faba. 
  

  

  Plate 
  32, 
  Figs. 
  1-3. 
  

  

  Leperditia 
  faba 
  Hall. 
  Doc. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat. 
  Hist. 
  Explanation 
  of 
  

   pi. 
  32, 
  figs. 
  1-3. 
  1876. 
  

  

  Form 
  subovate, 
  gibbous, 
  greatest 
  convexity 
  just 
  anterior 
  

   to 
  the 
  middle 
  ; 
  binge- 
  line 
  straight 
  and 
  equaling 
  two-thirds 
  the 
  

   length 
  of 
  the 
  shell 
  ; 
  width 
  of 
  the 
  shell 
  equal 
  to 
  three-fifths 
  of 
  

   the 
  length 
  ; 
  valves 
  subequal, 
  the 
  left 
  valve 
  the 
  larger 
  and 
  over- 
  

   lapping 
  at 
  the 
  base 
  ; 
  posterior 
  end 
  rounded, 
  narrower 
  than 
  

   the 
  anterior 
  ; 
  base 
  broadly 
  and 
  regularly 
  rounded 
  in 
  outline, 
  

   the 
  line 
  of 
  junction 
  of 
  the 
  two 
  valves 
  being 
  slightly 
  arcuate 
  

   laterally. 
  

  

  Surface 
  apparently 
  smooth. 
  

  

  BEYRICHIA 
  McCoy. 
  

   Beyrichia 
  granulosa. 
  

  

  Plate 
  32, 
  Fig. 
  4. 
  

  

  Beyrichia 
  granulosa 
  Hall. 
  Doc. 
  Edit. 
  28th 
  Rep. 
  St. 
  Mus. 
  Nat. 
  Hist. 
  Explana- 
  

   tion 
  of 
  pi. 
  32, 
  fig. 
  4. 
  1876. 
  

  

  Form 
  broadly 
  semioval 
  ; 
  dorsal 
  side 
  straight 
  ; 
  anterior 
  and 
  

   posterior 
  lobe 
  unequal 
  ; 
  the 
  ventral, 
  anterior 
  and 
  posterior 
  

   sides 
  bordered 
  b}^ 
  a 
  broad 
  flattened 
  rim 
  ; 
  subcentral 
  node 
  

   ovate, 
  extending 
  three-fifths 
  the 
  width 
  of 
  the 
  test, 
  and 
  about 
  

   one-fourth 
  as 
  wide 
  as 
  the 
  length 
  of 
  the 
  shell. 
  

  

  Surface 
  finely 
  tub 
  ercu 
  late. 
  

  

  

  