129 
elongated  spot  or  two  smoky  dots,  at  the 
point.  The  female  has  a  rather  long,  stout, 
downward  bent  ovipositor.  Trochanters, 
with  a  long  and  bent  hook  on  the  under 
side,  in  the  male;  with  a  tubercule,  in  the  fe¬ 
male;  both  with  a  corresponding  notch  on  the 
under  side  of  the  femora.  Abdomen  brown¬ 
ish-yellow,  variegated.  Lenght  of  body  13- 
lb  mm.  Testaceous  species,  with  brown 
spots  and  greyish  yellow  hairs;  thorax  with 
interrupted  belt  of  black  hairs,  behind  the 
suture  ;  more  rarely  with  reddish  hairs  only”. 
Gastrophilus  asininus  BRAUER 
(PI.  28,  fig  9.) 
Speaking  of  two  flies  bred  by  BILHARZ 
in  Egypt,  from  larvae  expelled  by  a  donkey, 
BRAUER  says: 
“Their  general  aspect  is  very  different 
from  all  my  specimens  of  C.  equi and  after  exa¬ 
mining  them,  both  Mr.  W1NNERTZ  and  Prof. 
WESTWOOD  thought  they  might  belong  to 
a  new  species.  They  differ  from  G.  equi  in 
the  following  things:  the  hairs  on  the  scutum 
are  uniformely  reddish  brown  ;  the  abdomen 
is  almost  free  from  spots;  the  wings  are 
much  wider  and  have  a  brown  streak  which 
is  much  broader  in  the  middle  than  at  the 
posterior  margin  ;  the  brown  color  extends 
to  the  back  of  the  fifth  longitudinal  vein.  A 
very  similar  specimen  from  Nubia  is  to  be 
found  in  WINTHEM's.  collection.  .  .  Should 
the  african  specimens  prove  te  belong  to 
another  species,  closely  allied  to  G.  equi ,  1 
propose  the  name  of  G.  asininus 
My  specimen  tallies  perfectly  with  BRAU- 
ER’s  description  and  is  clearly  different 
from  the  real  G.  equi  which  I  have  in  my 
collection.  I  am  sure  it  is  another  species  and 
consequently  accept  the  name  proposed  by 
BRAUER. 
The  ovipositor  is  clearly  shown  in  my 
specimen,  a  female  which  was  caught  in  the 
south  of  Minas.  It  is  almost  certain  that  it 
was  introduced  by  asses,  imported  for  the 
breeding  of  mules. 
(Note.  -  Dr.  ESPIR1D1ÃO  QUEIROZ  ob¬ 
served  the  emigration  of  several  larvae  from 
a  horse,  lately  arrived  from  Europe.  They 
probably  belonged  to  some  species  of  Gas¬ 
trophilus). 
On  the  parasitism  of  the  american  Oes- 
trinae. 
Dennatobia  ho  minis  has  been  observed  in 
a  vast  territory  aud  has  a  great  number  of 
very  different  hosts.  Of  these,  the  ox  is  now¬ 
adays  the  most  important  and  is  in  itself  quite 
sufficient  to  guarantee  the  active  propagation 
of  the  species  as  it  seems  unable  lo  get  rid 
of  et.  Dogs  used  in  hunting  commonly  show 
the  larvae  and  people  not  rarely.  The  horse, 
on  the  other  hand,  is  though  almost  entirely 
the  mules  also  in  a  lesser  degree.  This  fact  can 
not  be  due  to  a  defensive  act,  which  might 
explained  ityin  case  of  a  direct  transmission, 
but  not  in  that  of  an  indirect  one. 
The  other  kinds  of  Oestrinae  only  atack 
rodents.  BRAUER  claims  to  have  examined 
Cuterebra  larvae  found  by  NATTERER  in 
Sciurus  aestuans  and  Didelphis  philander  in 
Ipanema;  the  latter  must  be  an  exceptional 
case.  These  small  marsupials  mut  still  less 
be  included  among  the  hosts  of  Rogenhofera 
though  BAU  has  done  so.  During  35  years  I 
have  not  had  any  confirmation  whatever  of 
this  assertion  and,  in  the  last  10  years,  all  in¬ 
quiries  in  this  direction  gave  negative  results. 
Even  among  the  rodents,  only  a  few  spe¬ 
cies  are  attacked,  a  fact  which  proves  that 
the  Oestrinae  are  very  specialised  in  their 
choice  of  hosts.  The  most  affected  are  the 
native  Muridae  from  which  1  gathered  two 
kinds  of  Cuterebra  and  BERG  one  of  Rogen¬ 
hofera.  In  certain  places,  especially  on 
the  coast,  many  squirrels  (Sciurus  aestuans 
vulgo  caxinguelé  or  serelepe )  have  been  found 
with  larvae  differing  from  those  of  C.  apicalis 
by  their  darker  color,  more  like  that  of  C.  nigri¬ 
cans.  In  North-America  the  hares  are  attacked 
by  a  species  of  Cuterebra  and  of  Bogeria,  but 
Lepus  brasiliensis  seems  free  from  larvae  in 
the  skin.  It  is  strange  that  all  the  large  ro¬ 
dents  like  the  capivara  (water-hog)  the  aguti 
end  the  paca  seem  complety  immune  ;  the 
same  probably  applies  to  introduced  Muridae. 
