119 
The  scutum  is  almost  quadrangular  ;  the 
thorax  thick,  the  abdomen  slightly  detached 
and  always  rather  short  and  stout.  There 
are  no  macrochaetae.  The  female  may  have 
an  ovipositor.  There  are  always  fine  folds  or 
wrinkles  in  the  wings  which  are  of  the  or¬ 
dinary  type,  found  in  the  Muscae  calypteratae\ 
the  same  applies  to  the  legs. 
A  peculiarity  worth  mentioning  is  the  great 
likeness  between  most  of  these  species  and 
aculeate  Hymenoptera,  in  general  appearance 
as  well  as  in  the  way  of  flying  and  buzzing. 
This  explains  why  many  large  animals  are 
so  afraid  of  them. 
The  american  Oestridae  are  rather  diffe¬ 
rent  from  those  of  the  old  world,  though 
they  have  some  affinity  to  Cephenomyia.  The 
larvae  of  Dermatobia  somewhat  ressemble 
those  of  Hypoderma. 
Dermatobia  hominis  is  easily  distin¬ 
guished  from  all  other  american  species,  by  its 
small  size,  the  absence  of  hairs,  the  brickred 
eyes  (in  live  specimens),  striated  scutum,  hyali¬ 
ne  wings  and  metallic  blue  abdomen.  It  seems 
to  be  the  only  species  of  this  genus,  but  covers 
an  extensive  territory  and  has  a  long  list  of 
hosts  of  which  cattle,  though  introduced,  is 
the  most  important  and  suffices  alone  to  in¬ 
sure  the  continuity  of  this  species. 
The  other  brazilian  Oestridae  are  rather 
scarce  and  rarely  seen,  though  their  size,  quite 
uncommon  in  Muscidae ,  and  many  peculia¬ 
rities  in  their  appearance  draw  the  atten¬ 
tion  of  the  collector.  Of  the  other  genera, 
Caterebra  became  known  in  the  first  period 
of  systematic  dipterology;  species  of  Rogen- 
hofera  and  Pseudogametes  were  also  des¬ 
cribed,  though  without  the  later  distinction 
of  their  genera. 
With  the  help  of  the  above  mentioned 
monographs,  I  drew  up  a  key  for  the  Oestri- 
nae  observed  by  me  in  Brazil  : 
4 
2 
3 
Gastrophilus  LEACH 
5 
Rogenhojera  BRAUER 
6 
Pseudogametes  B1SCHOF 
Cuterebra  CLARK 
Dermatobia  MACQUART 
1.  Under  side  of  the  head  with  deep  longitudinal  fissure  contain¬ 
ing  the  proboscis  (Cuterebra  and  other  american  genera) 
The  same,  without  deep  fissure  (Oestrinae  typicae) . 
2.  Transversal  apical  vein  absent;  small  squamuae  (Gastricolae) 
3.  Empodia  and  ocelli  distinct . 
4.  Aristae  pennate . 
Arista  bare . 
5.  Arista  pennate,  on  the  upper  side  only . 
«  «  «  both  sides . 
6.  Face  with  callosities.  Tarsi  broad . 
«  without  callosities.  Tarsi  slender . 
Follows  a  list  of  South-american  species  : 
1.  Cuterebra  ephippium  LATR.  1817  Cayenne. 
2.  «  apicalis  GUÉR.  1829-38,  Brazil. 
3.  «  patagona  GUÉR,  1829-38.  Patagonia. 
4.  «  analis  MACQ.  1843,  Brazil. 
5.  «  cayennensis  MACQ.  1843,  Brazil. 
6.  «  rufiventris  MACQ,  1853.  Brazil. 
7.  «  megastoma  BRAUER,  1863,  South-America. 
8.  «  funebris  AUSTEN,  1895.  Trinidad. 
9.  «  nigricincta  AUSTEN,  1895.  Brazil. 
There  are  also  four  new  species  of  Cuterebra'. 
10.  Cuterebra  sarcophagoides  n.  sp.  Brazil  State  of  São  Paulo. 
11.  «  nigricans  n.  sp.  Brazil,  State  of  São  Paulo. 
12.  «  infulata  n.  sp.  Brazil,  State  of  Rio  de  Janeiro. 
13.  «  Schmalzi  n.  sp.  Brazil,  State  of  Santa  Catharina. 
