MR.  BRODERIP  ON  THE  GENUS  CHAMA. 
303 
transparent ;  and  the  white  valves  are  striped  or  tinged  externally  with  the  same 
colours.  In  old  specimens  the  foliations  and  lamellee  are  completely  worn  down,  and 
the  shell  has  somewhat  of  a  crystalline  appearance ;  indeed  it  is  always  semitrans- 
parent. 
Dredged  up  by  Mr.  Cuming,  attached  to  stones,  Mytili,  and  turbinated  shells,  at  a 
depth  varying  from  nine  to  eleven  fathoms,  from  a  bottom  of  coarse  sand ;  and  also 
found  under  stones  at  low-water  mark. 
Chama  lobata. 
Tab.  XXXVIII.  Figg.  4,  5. 
Chama  testa  alba,  lobata,  subrhomboided,  radiatim  striata,  lamellis  creberrimis,  fimbriatis, 
foliaceis,  striatis ;  limbo  interna  crenato. 
Hab.  ad  insulam  Nevis. 
This  shell  is  of  a  dead  white,  and  striated,  in  a  radiated  direction,  from  the  umbones 
(which  are  sometimes  tinged  with  brownish  or  yellowish)  to  the  borders  of  the  valves. 
The  foliated  fimbriations  are  close-set,  and  sometimes  very  much  developed.  The 
valves  are  sometimes  tinged  on  the  inside  towards  the  umbones  with  yellowish  and 
purplish ;  and  the  internal  border  is  strongly  crenated. 
It  was  found  attached  to  small  stones  and  shells  at  Nevis  in  the  West  Indies  in  sandy 
mud,  and  at  a  depth  ranging  from  four  to  ten  fathoms. 
Chama  sinuosa. 
Tab.  XXXVIII.  Fig.  6. 
Chama  testd  suborbiculari,  postice  sinuatd,  lamellis  mediocribus,  plicatis,  subdepressis,  alba 
rufo-spadiceo  maculatd;  intus  albd,  limbo  interno  Icevi. 
Hab.  ad  Brasiliam. 
This  species,  which  in  some  points  approaches  the  last,  was  brought  from  Brazil  by 
J.  Miller,  Esq.,  Surgeon  R.N.  The  differences  are  many,  as  will  be  seen  on  reference 
to  the  figure.  The  fine  strips  of  the  crowded  lamellcE,  so  remarkable  in  Chama  lobata, 
are  wanting  in  the  comparatively  distant  lamellcs  of  Chama  sinuosa,  which  has  the  in- 
ternal borders  of  the  valves  smooth. 
Chama  Pacifica. 
Tab.  XXXIX.  Fig.  1. 
Chama  testd  rubra,  purpurea  vel  luted,  lamellis  creberrimis,  foliis  sen  squamulis  brevioribus 
inter dum  albidis ;  limbo  interno  crenato. 
Hab.  in  Oceano  Pacifico.    (Lord  Hood's  Island,  Pearl  Islands.) 
The  infinite  varieties  of  this  species  in  shape  and  colour  defy  description.    In  many 
2  s  2 
