204 
MR.  BRODERIP'S  DESCRIPTIONS  OF  SOME 
Hah.  ad  Pemviam.    (Lobos  Island.) 
Approaching  the  last,  but  differing  in  being  always  more  flattened,  in  the  compara- 
tively great  size  of  the  vaulted  spines,  and  in  the  comparatively  wide  interval  between 
them.  Still  I  would  not  be  positive  that  both  are  not  varieties  of  Crepidula  acu- 
leata,  Lara. 
25,   CALYPTRyEA  PALLIDA. 
Tab.  XXIX.  Fig.  3. 
Cal.  testa  sordide  alba,  ovatd ;  apice  prominente. 
Diam.  -f  poll.,  lat.  »,  alt.  f. 
Hab.  ad  Insulas  Falkland  dictas. 
Found  under  stones. 
Subgenus  Crepidula,  Less. 
Lamina  subrecta,  apice  postico  et  submedio. 
26.  Crepidula  unguiformis,  Lam. 
Varietas  complanato-recurva. 
Tab.  XXIX.  Fig.  4. 
Long,  l-f-  poll.,  lat.  ^. 
Hab.  ad  Insulam  Chiloen  et  ad  Panamam. 
This  variety  affords  a  good  example  of  the  powers  of  adaptation  of  the  animal.  The 
shell  is  either  flattened  or  concave  on  the  back,  and  recurved,  in  consequence  of  its 
adhesion  to  the  inside  of  dead  shells  of  Ranellce  Vexillum,  coelata,  &c. 
It  was  dredged  from  sandy  mud,  at  a  depth  ranging  from  four  to  ten  fathoms. 
27.  Calyptr^a  Lessonii. 
Tab.  XXIX.  Fig.  5. 
Cal.  testd  complanatd,  subconcentrice  foliaced,  foliis  tenuibus,  alba  fusco  longitudinaliter 
strigatd,  intus  albidd,  limbo  interno  interdum.fusco  ciliato-strigato. 
Long.  1-V  poll.,  lat.       alt.  -|. 
Hab.  in  sinu  Guayaquil.    (Island  of  Muerte.) 
This  beautiful  species,  which  I  have  named  in  honour  of  M.  Lesson,  was  found  under 
stones  at  low  w^ater.  It  will  remind  the  observer  of  the  upper  valves  of  some  of  the 
Chama. 
28.  Calyptr^ea  incurva. 
Tab.  XXIX.  Fig.  6. 
Cal.  testd  fusco-nigricante,  tortuosd,  corrugatd,  intus  nigricante,  septo  albo ;  apice  adunco. 
Long,  i  poll.,  lat.  i,  alt.  f. 
Hab.  ad  Sanctam  Elenam  et  ad  Xipixapi. 
