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MR.  BRODERIP  ON  THE  GENUS  CHAMA. 
variety  is  infinite,  and  I  enter  upon  the  task  of  describing  the  following  specimens 
brought  home  by  Mr.  Cuming,  and  now  in  his  cabinet,  with  considerable  diffidence. 
Chama  frondosa. 
Tab.  XXXVIII.  Fig.  1. 
Chama  testa  sublohatd,  lamellosd,  lamellis  simosisfrondosis,  frondibus  longitudinaliter  pli- 
catis  et  in  utrdque  valvd  cardinem  versus  biseriatis,  maximis ;  intus  alba,  limbo  purpu- 
rascente,  crenulato. 
Hah.  ad  Insulam  Platam  Colombise  Occidentalis. 
The  ground  colour  of  this  beautiful  Chama  is  a  light  pinkish  purple,  and  the  luxu- 
riant and  spreading  longitudinally-plaited  foliations  are  yellow,  tinged  and  streaked  with 
the  ground  colour.  At  the  root  of  each  foliation  on  its  lower  side  there  is  generally  a 
purplish  transverse  stripe.  The  inside  of  the  valves  is  whitish,  and  their  internal  edge, 
which  is  crenulated  all  round,  is  bordered  with  dark  purple,  blending  into  yellow  at  the 
verge,  but  more  intense  at  the  posterior  edge. 
The  specimen  from  which  the  figure  and  description  were  taken  was  dredged  up  by 
Mr.  Cuming  from  a  rock  of  coral,  to  which  it  was  adhering  at  a  depth  of  seventeen 
fathoms. 
Var.  a.  Lamellis  crebrioribus,  frondibus  hrevioribus. 
Hah.  cum  preecedente. 
Found  attached  to  coral  at  the  same  island  where  the  specimen  last  described  was 
obtained,  and  at  about  the  same  depth. 
Var.  |8.  Tota  purpurea,  lamellis  creherrimis,  frondibus  brevissimis. 
Tab.  XXXVIII.  Fig.  2. 
Hah.  ad  Mexico.    (Gulf  of  Tehuantepec.) 
Dredged  up  from  sandy  mud  attached  to  Aviculee  {MeleagrincB,  Lam.,  Margarita, 
Leach),  at  a  depth  of  ten  fathoms. 
Traces  of  the  lobated  form  and  double  series  of  foliations  near  the  hinge  wiU  be  per- 
ceived more  clearly  in  variety  a.  than  in  variety  |3. ;  stiU  I  think  that  the  latter  is  only 
another  variety  of  Chama  frondosa.  Traces  of  the  yellow  colour  may  be  seen,  especially 
near  the  umbo. 
Chama  pellucida. 
Tab.  XXXVIII.  Fig.  3. 
Chama  testa  alba  roseo  seu  ruhro  fucatd  vel  strigatd,  lamellis  frequentibus,  frondibus  elon- 
gatis  pellucidis ;  intus  alhd,  Umbo  crenulato. 
Hah.  ad  Peruviam.  (Iquiqui.) 
This  pretty  species,  when  perfect,  has  its  white,  ruddy,  or  vinous  elongated  foliations 
