[   77  ] 
IX.  On  the  Anatomy  of  the  Sepiola  vulgaris,  Leach,  and  Account  of  a  New  Species 
(Sep.  stenodactyla,  Grant,)  from  the  Coast  of  Mauritius.  By  Robert  E.  Grant,  M.D., 
F.R.S.  Ed.,  L.S.,  G.S.,  Z.S.  ^c.  Professor  of  Comparative  Anatomy  and  Zoology  in 
the  University  of  London. 
Communicated  March  26,  and  July  23,  1833. 
The  Sepiola  vulgaris  is  one  of  the  most  minute  and  least  known  of  the  Naked  Cepha- 
lopods  inhabiting  the  shores  of  Europe.  It  can  scarcely,  however,  be  considered  as  a 
rare  animal ;  it  is  known  to  occur  in  the  Mediterranean,  and  other  parts  of  the  Euro- 
pean coasts,  and  has  been  met  with  as  far  north  as  Davis's  Straits.  I  have  met  with  it 
in  the  Frith  of  Forth,  and  have  often  obtained  recent  specimens  of  it  in  London,  brought 
up  with  fishes  from  our  eastern  coasts.  The  specimens  from  the  British  coasts  generally 
measure  from  an  inch  and  a  half  to  two  inches  in  length  from  the  round  base  of  the 
body  to  the  extreme  points  of  the  arms,  the  two  tentacula  being  commonly  as  long  as 
the  total  length  of  the  rest  of  the  animal.  This  interesting  little  Cephalopod  belongs  to 
that  division  of  the  class  termed  Decapoda,  or  Decacera,  from  the  species  possessing, 
besides  the  usual  eight  arms  around  the  head,  two  long  pedunculated  tentacula  which 
extend  from  within  the  brachial  disk.  Like  the  animals  of  the  genus  Loligo,  this  De- 
capod has  a  thin  flexible  transparent  dorsal  lamina  and  fin-like  organs,  extending  from 
the  sides  of  the  body  to  assist  in  progressive  motion ;  and  it  has  generally  been  ranked 
as  a  species  of  Loligo  by  Cuvier,  Lamarck,  M.  Blainville,  and  other  systematic  writers. 
The  shortness  of  its  body  and  its  rounded  termination  form,  however,  so  remarkable  an 
exception  to  the  usual  form  in  the  genus  Loligo,  that  Dr.  Leach  was  induced  to  esta- 
blish a  new  genus  for  this  peculiar  type,  retaining  for  it  the  original  specific  name  of 
Sepiola,  which  had  been  given  to  it  from  its  external  affinities  to  Sepia.  This  peculiar 
form  had  been  hitherto  known  only  as  belonging  to  the  single  species  of  the  European 
coasts,  the  Sepiola  vulgaris. 
It  might  have  been  expected  that  an  external  form  differing  so  remarkably  from  that 
of  the  other  Loligines,  would  have  earlier  excited  the  curiosity  of  the  anatomist  to  ex- 
amine, in  an  animal  so  common  on  the  coasts  of  Europe,  whether  or  not  there  were 
corresponding  peculiarities  of  internal  structure,  particularly  as  the  animals  of  this  class 
are  known  to  present  many  interesting  peculiarities  in  the  different  species.  The  small 
size  of  the  Sepiola  appears,  however,  to  have  hitherto  concealed  it  from  anatomical  ex- 
amination, as  no  observations  have  been  recorded,  so  far  as  I  know,  regarding  any  of 
its  internal  organs.  This  little  Cephalopod  is  remarkable  for  the  great  size  of  its  head 
and  arms  compared  with  the  smallness  and  shortness  of  the  body ;  its  lateral  fins  are 
