MR.  BRODERIP  ON  THE  GENUS  CHAMA. 
305 
Chama  producta. 
Tab.  XXXIX.  Fig.  4. 
Chama  testa  subpurpured,  creberrime  lamellosd,  lamellis  foliaceis,  integris ;  valvd  inferiors 
enormiter  productd ;  limbo  integro,  purpureo. 
Hob.  ad  Mexico.    (Gulf  of  Tehuantepec.) 
The  closely  set  foliaceous  lamellcB  on  the  upper  valve  are  almost  entirely  abraded  in 
the  specimen  before  me,  which,  it  should  be  remembered,  bears  the  marks  of  consider- 
able age.  Those  on  the  enormously  produced  lower  valve  are,  on  one  side,  in  good 
preservation,  and  are  not  unlike  in  appearance  to  those  of  some  of  the  Spondyli  when 
they  have  grown  in  the  same  fashion.  The  interior  of  the  shell,  which  has  something 
of  the  aspect  of  a  Gryphtsa,  is  white  tinged  with  yellowish,  and  striped  in  the  direction 
of  the  lamella  with  purple.  The  purple  border  on  the  smooth  internal  edge  of  the  upper 
valve  is  of  some  width. 
Dredged  up  by  Mr.  Cuming  from  sandy  mud  at  a  depth  of  ten  fathoms,  attached  to 
stones. 
Chama  corrugata. 
Tab.  XXXVIII.  Fig.  7. 
Chama  testd  corrugatd,  rubro-purpured  albo  varid;  intus  atro-purpured,  limbo  integro. 
Hab.  in  America  Centrali.    (Real  Lleijos.) 
Found  by  Mr.  Cuming  attached  to  stones  at  low  water.  All  the  specimens  which  I 
have  seen  turn  from  right  to  left. 
Chama  echinata. 
Tab.  XXXIX.  Fig.  5,  (Junior)  ;  6,  7  (Senior). 
Chama  testd  albidd  purpureo  varid,  spinis  fornicatis  echinatd ;  intus  atro-purpured  vel  sub- 
rubrd,  limbo  integro  ;  dente  cardinali  rubro. 
Hab.  in  America  Centrali.    (Puerto  Portrero.) 
The  spines  of  this  species,  which  are  close-set  and  well  developed  in  youth,  are  en- 
tirely abraded  in  age  till  nothing  but  corrugation  is  left  externally.  But  as  the  animal 
advances  in  life,  the  interior  of  the  shell  is  richly  painted,  till  in  old  age  it  arrives  to  an 
intensity  of  dark  purple  difficult  to  imitate  with  colours  however  rich.  At  that  period 
the  cardinal  tooth  becomes  of  the  hue  of  the  bone  of  the  red  Coral  (Isis  nobilis),  used 
for  ornamental  purposes.  Fig.  6.  represents  the  interior  of  the  lower  valve,  and  Fig.  7. 
the  interior  of  the  upper  one. 
Found  at  low  water  attached  to  rocks. 
