Извѣстія  Роесійекой  Акадѳміи  Наукъ.  1919, 
(Bulletin  de  ГАсасІѳгаіѳ  des  Sciences  de  Russie). 
On  a  nem^  speeies  of  the  genus  Pemphigus  fL&r tig 
f  living  on  the  Älder^trees, 
J3y  INT.  Cholodkoizsky. 
(Presented  to  the  Academy  by  N.  V,  Nasonov,  Member  of  the  Academy;  the  26  of  March  1919). 
In  the  year  1915  I  received,  among  other  scientifical  materials 
brought  by  M.  G,  Doppelmayr,  member  of  the  Bargusin  Expedition 
(from  the  Transbaicalian  province),  a  colony  of  Aphides  m  alcohol  col- 
lected in  August  1914  on  the  Alder  leaf  curled  downward.  There 
were  winged  and  apterous  individuals  of  various  developmental  stages, 
covered  with  much  white  cottony  secretion  partly  insoluble  even  in 
alcohol.  When  examined  these  Aphides  proved  to  belong  to  the  genus 
Pemphigus  Hartig.  I  have  nothing  to  say  about  the  natural  colour  of  these 
insects,  having  at  my  disposition  the  alcohol  specimens  only,  and  the  label 
put  in  the  bottle  containing  no  indications  relating  to  it.  The  length  of 
the  body  of  the  winged  individual  is  about  3,5  mm.,  the  diameter  of  the 
thorax  —  about  1,25  mm.,  while  the  mature  apterous  individual  is  about 
3  mm.  long  and  about  1,35  mm.  broad.  The  antenna  of  the  winged  individual 
is  about  І  mm.  long,  its  joint  3.  being  the  longest  of  all  and  somewhat 
shorter  than  the  joints  4.  and  5.  together,  while  the  joint  4.  is  a  fewr  shorter 
than  the  5.,  and  the  5.  somewhat  shorter  than  the  6  (Fig.  1).  The  joints  6. 
Fig.  1 .  An  antenna  of  the  winged  Pemphigus  baicalensis  sp,  n.  Zeiss  AA,  Oc.  4. 
and  5.  bear  each  a  tortuously  contoured  primitive  rhinary,  and  the  rhinary 
of  the  5.  joint  contains  in  its  midst  2 — 3  small  complemental  rhiuaries. 
Извѣстія  P.  Л  H.  1010.  —  78/  — 
