﻿Report 
  of 
  tre 
  State 
  Geologist. 
  

   Bouchardia, 
  Davidson. 
  1849. 
  

  

  1087 
  

  

  Synonym 
  ; 
  Pachyhrynchus, 
  King, 
  1850. 
  

  

  Shells 
  elongate-oval; 
  surface 
  smooth. 
  Beak 
  of 
  the 
  pedicle- 
  

   valve 
  elevated, 
  subacute, 
  truncated 
  by 
  a 
  circular 
  foramen. 
  Del- 
  

   tidial 
  plates 
  coalesced, 
  concave. 
  Interiorly 
  both 
  valves 
  much 
  

   thickened 
  in 
  the 
  umbonal 
  region. 
  Teeth 
  and 
  sockets 
  much 
  

   abbreviated. 
  In 
  the 
  pedicle-valve 
  the 
  adductor 
  and 
  diductor 
  

   scars 
  are 
  situated 
  anteriorly 
  and 
  divided 
  by 
  a 
  low 
  median 
  ridge. 
  

  

  Figs. 
  620-622. 
  Bouchardia 
  rosea, 
  Mawe 
  (sp.) 
  . 
  (Davidson.) 
  

  

  In 
  the 
  brachial 
  valve 
  is 
  an 
  elongate 
  rectangular 
  bilobed 
  cardinal 
  

   process, 
  which 
  fits 
  into 
  the 
  deep 
  pedicle-groove 
  of 
  the 
  opposite 
  

   valve. 
  Median 
  septum 
  developed 
  anteriorly. 
  Brachidium 
  with- 
  

   out 
  the 
  descending 
  branches 
  ; 
  ascending 
  branches 
  represented 
  by 
  

   two 
  broad, 
  curved 
  triangular 
  processes 
  coalesced 
  with 
  the 
  sep- 
  

   tum 
  below 
  and 
  not 
  uniting 
  above. 
  

  

  Type, 
  Bouchardia 
  rosea, 
  Mawe 
  (sp.). 
  

  

  Distribution. 
  Recent 
  (Caribbean 
  Province). 
  

  

  Magas, 
  Sowerby. 
  1816. 
  

  

  Shells 
  small, 
  subplano-convex. 
  Surface 
  smooth. 
  Pedicle- 
  

   valve 
  deep, 
  with 
  incurved 
  umbo. 
  Foramen 
  sub 
  triangular, 
  del- 
  

   tidial 
  plates 
  feebly 
  developed. 
  Brachial 
  valve 
  with 
  a 
  well- 
  

   developed 
  cardinal 
  process, 
  and 
  very 
  prominent 
  median 
  septum. 
  

   Descending 
  branches 
  of 
  the 
  loop 
  joined 
  to 
  the 
  walls 
  of 
  this 
  sep- 
  

  

  145 
  

  

  