232 
MR.  G.  BENNETT  ON  THE  HISTORY  AND  HABITS  OF 
will :  in  dead  specimens,  being  closed,  it  would  not  be  readily  perceived  by  a  person 
unacquainted  with  its  exact  situation.  From  this  orifice  a  semicircular  cartilaginous 
canal  is  continued,  terminating  at  the  base  of  the  skull. 
The  Ornithorhynchus  has  a  peculiar  fishy  smell,  more  especially  when  wet,  which 
probably  proceeds  from  an  oily  secretion.  The  aborigines  use  these  animals  as  food : 
but  it  is  no  particular  recommendation  of  them  to  say  that  they  are  eaten  by  the  Native 
Australian,  as  nothing  in  the  shape  of  provender  comes  amiss  to  him,  whether  it 
be  snakes,  rats,  frogs,  grubs,  or  the  more  delicate  Opossum,  Bandicoot  and  Flying 
Squirrel. 
There  are  two  species  usually  described  in  our  works  on  Natural  History,  the  Orni- 
thorhynchus rufus  and  the  Orn.  fuscus ;  but  the  differences  between  them  appear  to  me 
to  be  so  unimportant  that  I  hesitate  in  considering  them  as  otherwise  than  specifically 
identical.  Not  having  referred  the  Water-Moles  which  fell  under  my  observation  to 
either  of  these  presumed  species,  I  retain  for  them  the  name  originally  proposed  by 
Professor  Blumenbach,  that  of  Orn.  paradoxus :  though  subsequent  in  date  to  the  de- 
nomination assigned  by  Shaw  to  the  same  animal,  it  has  been  so  extensively  adopted  as 
to  render  it  inexpedient  in  this  instance  to  adhere  to  the  strict  rule  of  nomenclature. 
The  size  of  the  Ornithorhynchus  varies,  but  the  males  are  usually  found  to  be  in  a 
small  degree  larger  than  the  females :  the  average  length  I  consider  to  be  from  1  foot 
6  inches  to  1  foot  8  inches.  From  the  following  dimensions  of  specimens  shot  in  the 
Yas  and  Murrumbidgee  rivers^  an  idea  may  be  formed  of  the  relative  proportions  of 
the  different  parts  to  the  body :  the  measurements  were  taken  immediately  after  the 
animals  had  been  shot  and  removed  from  the  water,  the  specimens,  still  in  their  flaccid 
state,  being  placed  in  their  natural  position.  On  the  dimensions  thus  taken  more  de- 
pendence can  be  placed  for  accuracy  than  on  those  derived  from  stuffed  specimens, 
which,  from  the  contracted  state  of  most  of  the  parts,  and  the  artificial  elongation  given 
to  the  body,  cannot  be  relied  on.  As  the  integuments,  moreover,  hang  very  loose 
about  the  animal,  they  are  usually  distended  by  the  stuffer  to  a  much  greater  degree 
than  is  natural. 
Male  specimen  shot  in  the  Yas  River. 
Ft.  In. 
Length  from  the  extremity  of  the  mandible  to  the  extremity  of  the  tail    1  7f 
Length  of  the  upper  mandible   2^ 
Breadth  of  the  upper  mandible   24- 
Length  of  the  lower  mandible   H 
Breadth  of  the  lower  mandible   H 
Length  of  the  fore  leg   3-|- 
'  Mr.  George  MacLeay  informs  me  that  the  specimens  procured  from  the  Nepean  River  are  seldom  longer 
than  1  foot  2  inches. 
