80 
DR.  R.  E.  GRANT  ON  THE  ANATOMY  OF  SEPIOLA  VULGARIS, 
of  considerable  size,  and  extends  to  a  great  length  from  the  sac ;  the  lateral  valvular 
prolongations  of  its  base  are  broad,  and  pass  deep  into  the  cavity  of  the  mantle.  About 
the  middle  of  the  dorsal  surface  of  the  canal  of  the  syphon,  is  seen  the  usual  tongue-like 
valvular  fleshy  fold,  extending  forwards,  with  a  cavity  behind  it  like  that  of  the  semi- 
lunar valves  of  the  heart  of  Mammalia,  and  serving  for  the  same  purpose.  This  valve 
of  the  syphon,  and  the  lateral  prolongations  of  the  base  of  the  funnel  within  the  mantle, 
serve  to  direct  the  currents  of  water  in  respiration ;  and  the  former  protects  the  viscera 
of  the  sac  from  the  impulse  of  the  water  when  the  animal  is  swimming  forwards,  as  the 
valvular  nostrils  of  diving  Mammalia. 
The  cavity  of  the  mantle  is  comparatively  small  in  this  Cephalopod,  and  its  whole 
extent  is  occupied  by  the  abdominal  and  pelvic  viscera.  The  genital  organs,  as  in  higher 
classes,  occupy  the  bottom  of  the  cavity,  and  the  digestive  organs,  as  usual,  lie  imme- 
diately above  them.  The  circulating  and  respiratory  organs  occupy  the  middle  of  the 
sac,  and  the  liver  and  ink  gland  its  upper  part.  From  the  back  part  of  the  base  of  the 
syphon,  two  strong  muscular  bands  pass  forwards  and  downwards  on  each  side  of  the 
anus,  and  are  attached  to  the  anterior  portion  of  the  sac  on  its  inner  surface.  These  two 
strong  muscles,  which  first  present  themselves  on  opening  the  sac,  are  calculated  to  act 
as  a  frdBnum  to  limit  the  dilatation  of  the  mantle.  As  the  rectum  passes  up  to  the  base 
of  the  funnel  between  them,  they  may  act  as  a  sphincter  to  the  anus  ;  and  as  they  pass 
over  the  two  lateral  lobes  of  the  ink  gland,  they  also  serve  to  compress  powerfully  that 
organ,  and  expel  the  ink  when  required.  All  the  viscera  contained  in  the  sac  are 
largely  developed  in  this  minute  Cephalopod,  particularly  the  digestive  organs,  the  ink 
gland,  and  the  two  glands  of  the  oviducts.  The  entrance  of  the  alimentary  canal  is 
provided  with  powerful  organs  of  prehension  in  the  large  muscular  arms  with  their 
pedunculated  suckers,  and  with  strong  organs  of  mastication  in  the  density  of  the  man- 
dibles, and  the  magnitude  of  their  muscles.  The  tentacula,  however,  are  not  provided 
with  suckers  at  their  extremities  ;  they  present  here  a  villous  surface,  on  the  usual  place 
of  the  suckers  in  Loligo  and  Sepia.  The  minute  filaments  of  this  villous  part  of  the 
tentaculum,  when  examined  through  a  lens,  present  the  appearance  of  very  small  soft 
transparent  suckers,  incapable  of  performing  their  ordinary  function.  The  mouth,  sur- 
rounded by  the  usual  double  muscular  fold,  is  provided  with  a  short,  broad,  fleshy 
tongue,  covered  with  strong  white  shining  recurved  teeth.  Some  of  the  larger  teeth, 
arranged  like  a  comb  on  the  anterior  part  of  the  tongue,  have  their  points  of  a  brown 
colour,  as  we  observe  in  the  larger  Cephalopods.  On  removing  the  oral  apparatus  from 
the  cup-like  cavity  which  it  occupies  immediately  above  the  CESophageal  ganglia,  we 
perceive  a  large  white  nervous  trunk  passing  from  the  anterior  ganglion  of  the  esophagus 
to  the  base  of  each  of  the  arras  around  the  mouth.  These  eight  large  nerves  pass  in  a 
radiating  manner  along  the  floor  of  this  cavity,  and  the  nerves  of  the  two  tentacula  come 
from  the  same  part  by  more  than  one  trunk  on  each  side.    The  tentacula  themselves 
