50 
MR.  E.  T.  BENNETT  ON  THE  CHINCHILLID^. 
of  the  laryiu  in  a  flattened  form,  the  two  portions  being  united  below  by  a  thin  trans- 
verse band,  which,  in  Cliinc/tllln,  was  scarcely  distinguishable.  The  lesser  cornua  of 
the  OS  hi/oides  wore  united  by  hgament  to  the  tympanic  bone.  In  the  soft  palate,  the 
hilcral  cohiinns  converged,  and  were  placed  near  to  each  other  in  the  posterior  part  of 
the  fauces,  leaving  a  large  cul-de-sac  external  to  them  on  each  side,  and  a  very  small 
openini;  to  the  pharynx  between  them.  The  interior  of  the  meatus  auditorius  was  smooth 
and  white.  In  Lmjotls  the  pupil  was  found  contracted  in  an  elliptical  form,  the  long 
diameter  being  obliquely  downwards  and  forwards  :  in  Chinchilla  it  was  exactly  circular. 
The  crvstallinc  lens  was  in  both  cases  large  and  more  than  usually  convex,  its  antero- 
posterior diameter  in  Chinchilla  being  to  its  lateral  nearly  as  4  to  5. 
In  Lagotis  the  epididymis  was  seen  projecting  through  the  external  ring ;  and  the  ex- 
ternal obliciue  muscle  in  both  exhibited  very  httle  of  a  tendinous  expansion.  The  in- 
testines of  both  had  the  tenuity  common  to  the  Rodentia.  In  Lagotis,  the  duodenum, 
after  descending  to  the  right  iliac  region,  made  a  fold  by  a  sudden  turn  upon  itself,  and 
returning  upwards  became  iree  after  crossing  the  spine  in  the  epigastric  region.  Within 
the  fold,  the  apex  of  which  was  connected  by  a  process  of  peritoneum  to  the  right  iliac 
region,  were  contained  at  its  upper  part  the  descending  lobes  of  the  pancreas.  This 
organ  was  large,  and  extended,  as  usual,  from  the  spleen  behind  the  stomach,  sending 
off  processes  down  the  mesoduodenum.  The  caecum  was  of  large  size,  and  occupied  the 
left  side  of  the  abdomen  :  it  was  of  a  sacculated  structure,  like  that  of  the  colon,  and 
connected  by  a  small  process  of  peritoneum.  Where  the  ileum  entered  the  large  intes- 
tine, the  latter  oflered  a  considerable  enlargement,  below  which  the  caecum  descended, 
of  nearly  equal  size  with  the  colon,  passed  spirally  downwards  and  backwards  for  nearly 
a  complete  turn,  and  then  bending  upon  itself  returned  in  such  a  manner  as  to  form  a 
second  nearly  complete  turn,  the  end  of  which  curved  over  and  was  directed  downwards 
at  its  termination  in  the  blind  extremity.  The  colon  continued  of  the  same  sacculated 
structure  across  the  pubic  region,  and  up  the  right  side  of  the  abdomen  as  far  as  the 
hypochondrium,  and  then  returned  suddenly  upon  itself,  the  descending  and  ascending 
portions  of  the  fold  thus  produced,  which  was  six  inches  in  length,  being  intimately 
connected  together  and  attached  to  the  same  process  of  peritoneum.  Towards  the  end 
of  this  fold  the  ffcces  began  to  be  formed  into  pellets,  and  the  sacculated  character  of 
the  colon  became  less  marked.  A  second  fold  of  a  similar  character  to  the  last,  with 
its  two  portions  similarly  united,  lying  loose  in  the  cavity  of  the  abdomen,  and  measuring 
a  foot  in  length,  succeeded.  Beyond  this  the  intestine  was  much  contracted,  its  coats 
becoming  transparent  in  consequence  of  their  extreme  tenuity  ;  and  the  remainder  of 
the  colon  formed  several  convolutions  on  the  left  side  of  the  abdomen.  The  entire  length 
of  the  small  intestines  was  seven  feet  four  inches,  and  that  of  the  large,  nine  feet  three 
inchen  ;  the  distance  between  the  mouth  and  the  anus  measuring  one  foot  and  an  inch. 
The  intestines  of  Chinchilla  were  on  the  whole  of  similar  character,  and  for  the  most 
part  disposed  in  the  same  manner  :  they  oflered,  however,  several  peculiarities  in  detail, 
