NEW  SPECIES  OF  CALYPTRiEID^. 
201 
the  passages  are  so  very  gradual,  it  is  difficult  to  come  to  a  satisfactory  conclusion  from 
an  unassisted  description,  however  well  written  it  may  be. 
13.  Calyptr/ea  sordida. 
Tab.  XXVIII.  Fig.  2. 
Cal.  testa  subconicd,  sordide  luted,  longitudinaliter  subradiatd ;  apice  turbinato ;  cyatho  de- 
presso,  subtrigono,  haud  prof  undo. 
Diam.     poll.,  lat.  iV,  alt.  -rV- 
Hab.  ad  Panamam. 
This  species,  the  inside  and  outside  of  which  are  of  a  sordid  yellow,  is  generally 
covered  externally  with  coral  or  other  marine  adhesions.    The  plate  is  spoon-shaped. 
Found  on  stones,  on  a  sandy  bottom,  at  a  depth  of  twelve  fathoms. 
14.  Calyptr/ea  Unguis. 
Tab.  XXVIII.  Fig.  3. 
Cal.  testa  tenui,  conicd,  corrugatd,  fused ;  apice  subturbinato  ;  cyatho  depresso,  subtrigono. 
Diam.      poll.,  alt.  -j^. 
Hab.  ad  Valparaiso. 
The  plate  is  spoon-shaped,  but  not  so  shallow  as  that  of  Cal.  sordida. 
Found  on  shells  at  a  depth  of  from  seven  to  forty-five  fathoms. 
15.  Calyptr/ea  Lichen. 
Tab.  XXVIII.  Fig.  4. 
Cal.  testa  albidd,  interdum  pallide  fusco  sparsd,  subdiaphand,  subturbinatd,  orbiculatd, 
complanatd. 
Diam.  -f-  poll.,  alt.  -f-. 
Hab.  in  sinu  Guayaquil.    (Island  of  Muerte.) 
Found  on  dead  shells  in  sandy  mud,  at  a  deptJi  of  eleven  fathoms. 
16.  Calyptr^ea  mamillaris. 
Tab.  XXVIII.  Fig.  5. 
Cal.  testa  albidd,  subconicd;  apice  subpurpureo,  mamillari. 
Diam.      poll.,  alt.  -jV- 
Hab.  in  sinu  Guayaquil.    (Island  of  Muerte.) 
This  pretty  species  varies.  It  is  sometimes  milk-white,  with  the  mamillary  apex  of 
a  brownish  purple,  and  with  the  inside  sometimes  of  that  colour,  sometimes  white,  and 
sometimes  yellowish.  In  other  individuals  the  wdiite  is  mottled  with  purplish  brown 
stripes  and  spots. 
Found  on  dead  shells  in  sandy  mud,  at  a  depth  of  eleven  fathoms. 
