22 
DR.  R.  E.  GRANT  ON  THE  GENUS  LOLIGOPSIS, 
velopraent  of  the  tentacula,  which  are  the  most  mutable  of  the  parts  around  the  mouth, 
assuming  various  forms,  and  being  sometimes  entirely  wanting.  They  are  present  in 
Loligo,  absent  in  Octopus;  and  in  the  animal  which  forms  the  subject  of  this  commu- 
nication, they  are  perceptible  only  in  a  rudimentary  state.  The  Cephalopods  present 
differences  of  structure  so  remarkable  as  to  render  it  impossible,  in  the  present  state 
of  our  acquaintance  with  them,  to  determine  what  characters  even  of  an  external 
nature  are  incompatible  with  each  other,  or  necessarily  concomitant. 
The  Cephalopod  represented  in  the  accompanying  drawings  (Plate  II.  figg.  2.  &  seq.) 
was  taken  in  the  Indian  Ocean  by  my  late  intelligent  pupil  Mr.  Cotton,  Surgeon  in  the 
Honourable  East  India  Company's  service,  and  was  sent  to  me  along  with  many  other 
interesting  marine  animals  collected  by  him  during  his  second  voyage  to  India.  It 
has  the  lengthened  tapering  form  of  body,  the  eight  sessile  arms,  and  the  circular 
caudal  appendix  of  the  other  two  known  species  of  Loligopsis ;  but  it  differs  from  them 
in  the  comparative  length  of  the  different  arms, — a  character  by  which  they  also  differ 
from  each  other.  The  Loligopsis  Peronii,  according  to  Lamarck,  has  the  eight  arms  of 
equal  length ;  the  Lol.  cyclura,  according  to  M.  Le  Sueur,  has  the  upper  and  the  inferior 
pair  of  arms,  nearly  of  equal  length  ;  and  in  the  Lol.  guttata  the  upper  pair  of  arms  are 
at  least  a  third  shorter  and  smaller  than  any  of  the  other  pairs.  The  whole  length  of 
the  present  species,  from  the  point  of  the  longest  arms  to  the  end  of  the  tail,  is  four  inches 
and  three  quarters  ;  the  specimen  of  M.  Le  Sueur  measured  five  inches  and  a  half;  and 
that  of  Lamarck  was  like  a  small  Sepiola,  that  is,  about  two  inches  long :  so  that  this 
singular  type  is  probably  confined  to  small  Cephalopods,  and  has  thus  escaped  more 
general  observation.  Independently,  however,  of  its  external  peculiarities,  it  presents 
modifications  of  internal  structure  hitherto  met  with  in  no  other  Naked  Cephalopods, 
and  which  serve  to  connect  the  latter  forms  with  the  Testaceous. 
Externally  this  animal'  has  much  resemblance  to  a  young  individual  of  the  common 
Loligo  sagittata  deprived  of  its  long  tentacula.  It  has  the  same  lengthened  tapering 
form  of  the  body,  short  cephalic  arms,  dark  brown  spotted  surface,  and  rounded  ter- 
minal fin.  Every  part  of  the  surface,  from  the  point  of  the  arms  to  the  extremity  of 
the  tail,  is  closely  covered  with  dark  brown  spots,  chiefly  of  two  sizes ;  the  larger  are 
minute  angular  patches  of  irregular  form,  and  the  smaller  are  very  minute  dark  points, 
filling  up  the  interstices  between  the  polygonal  patches.  These  spots  extend  into  the 
interior  of  the  mantle,  and  cover  closely  the  surface  of  the  four  separate  lobes  of  the 
liver.  There  are  several  large,  round,  and  very  obvious  patches  of  the  same  deep  brown 
colour  on  the  caudal  half  of  the  trunk,  which  have  a  somewhat  symmetrical  arrange- 
ment ;  eleven  of  these  are  seen  on  the  dorsal  surface,  and  nine  on  the  ventral.  It  is 
not  probable  that  these  large  circular  spots  will  be  found  identical  in  number  and  ar- 
rangement in  other  species,  although  from  their  size  and  symmetrical  order  they  may 
be  constant  in  this ;  I  have  therefore  taken  the  trivial  name  of  the  present  species  from 
'  Plate  II.  figg.  2.  and  3. 
