CUVIER'S  FAMILY  OF  BRACHIOPODA. 
143 
length  being  taken  from  the  extreme  edge  of  the  border  above  the  perforation  to  the 
opposite  rim ;  and  the  breadth  following  an  imaginary  line,  bisecting  the  former  at 
right  angles. 
2.  Orbicula  Cumingii. 
Tab.  XXIII.  Fig.  1. 
Orb.  testa  subconicd,  suborbiculari,  crassiusculd,  striis  ab  apice  radiantibus  numerosis ; 
epidermide  fused. 
Long.  ^  poll.,  lat. 
Hob.  ad  Paytam  Peruvise,  ad  Sanctam  Elenam,  et  ad  Panamam. 
Mus.  Cuming. 
The  concentric  lines  of  growth  in  this  species  are  crossed  by  the  numerous  stricB  which 
radiate  from  the  apex  of  the  upper  valve.  The  under  valve,  which  varies  from  con- 
vexity to  flatness,  is  much  the  thinnest,  and  is  only  marked  by  the  concentric  lines. 
Found  by  Mr.  Cuming  at  the  localities  above  given,  attached  to  the  lower  sides  of 
stones  in  sandy  mud  at  low  water,  and  in  some  instances  at  a  depth  of  six  fathoms. 
The  remains  of  the  cilia  give  a  bearded  appearance  to  the  border  of  the  shell  in  many 
of  the  dried  specimens,  as  in  Orb.  lamellosa. 
Orb.  Cumingii  approaches  nearest  to  Orb.  striata,  described  by  Mr.  G.  B.  Sowerby  in 
the  '  Transactions  of  the  Linnean  Society'. 
3.  Orbicula  strigata. 
Tab.  XXIII.  Fig.  1*. 
Orb.  testd  crassiusculd,  subrotundd,  substriatd,  radiatim  castaneo  strigata ;  epidermide 
tenui,  fused. 
Long.  -iV,  lat.  vix  -t-V>  crass.  poll. 
Hab.  ad  Guatemalse  oras.  (Isle  of  Caha.) 
Mr.  Cuming  dredged  two  individuals  of  this  species  at  the  depth  of  eighteen  fathoms. 
They  were  attached  to  rocks.  The  dimensions  are  taken  from  the  largest  specimen ; 
but  the  smallest  is  figured  on  account  of  the  superior  brilliancy  of  the  stripes. 
Genus.  Lingula,  Brug. 
1.  Lingula  Audebardii. 
Tab.  XXIII.  Fig.  14. 
Ling,  testd  oblongd,  glabra,  corned,  pallide  flavd,  viridi  transversim  pictd,  limbo  anteriore 
rotundato,  viridi. 
Long.  If  poll.,  lat.  t^-- 
Hab.  ad  Insulam  Punam.  (Bay  of  Guayaquil.) 
Mus.  Cuming. 
