A  Contribution  to  the  Study  of  parasitic  Ciliata 
by 
DR.  CESAR  FERREIRA  PINTO 
(With  Plate  76) 
Introduction. 
While  examining  the  intestine  of  some 
frogs  ( Leptodactylus  ocellatus)  from  Mangui- 
nhos  and  other  localities  of  Rio  de  Janeiro, 
1  found,  among  other  Ciliata  and  Flagellata, 
an  apparently  new  species  of  Opalina. 
In  the  blood  of  the  same  frogs  I  found 
Trypanosoma  rotatorium  GRUBY,  which  was 
studied  by  ASTROGILDO  MACHADO  and 
a  hemogregarine  which  I  intend  to  describe 
in  a  future  paper. 
Opalina  brasiliensis  PINTO,  1918. 
(PI.  76  figs  3a,  10  6  11). 
LÉGER  and  DUBOSQ  (Arch,  de  Zool. 
Expér.  sér.  4,  tome  2,  p.  343, 1913)  divide  the 
genus  Opalina  in  two  groups,  according  to 
the  number  of  nuclei:  a)  Opalinae  with  many 
nuclei  and  b)  Opalinae  with  from  one  to 
five.  O.  brasiliensis  PINTO  belongs  to  the 
latter,  since  it  has  from  one  to  four  nuclei. 
Fresh  material. 
Unstained  specimens  of  this  species  have 
a  yellowish  colour.  The  nuclei  are  visible 
and  the  endoplasm  contains  a  great  many 
rounded  or  rod-shaped  granulations.  The 
body  moves  rapidly  and  displaces  itself 
forwards  or  sideways  with  a  certain  amount 
of  agility.  Cilia  are  visible  on  the  whole 
outline. 
Morphology  and  Size. 
Opalina  brasiliensis  is  pear-shaped  and 
has  a  slight  elevation  to  one  side  of  its  anterior 
end,  while  its  posterior  extremity  ends  in  a 
blunt  point,  which  is  sometimes  also  deflec¬ 
ted  to  one  side.  The  specimens  I  observed 
were  46  p  long  and  22  p  wide.  Larger  forms 
may  attain  a  length  of  115  p  and  a  width  of 
from  10  to  12  p. 
Stained  Material. 
Methods. 
The  specimens  were  fixed  in  their  na¬ 
tural  medium  by  an  alcohol-sublimate  solu¬ 
tion  (Schaudinn)  and  stained  with  iron-he¬ 
matoxylin  (Heidenhain). 
Structure  of  the  Protoplasm. 
The  cytoplasm  is  divided  in  ectoplasm 
and  endoplas.n.  The  ectoplasm  is  more  or 
less  homogenous  and  of  yellowish  colour; 
many  cilia  issue  from  its  edge.  The  endo¬ 
plasm,  which  is  brown,  contains  many 
