—  790  — 
may  not  belong  to  the  genus  Prodphilus  Koch  but  to  the  genus  Pem- 
phigus Hart  which  is  deprived  of  such  glands. 
Our  Transbaicalian  species  as  mentioned  above,  also  belongs  to  the 
genus  Pemphigus,  but  it  differs  from  the  American  species  in  the  structure 
of  the  antennae.  Namely,  the  sixth  joint  of  the  antenna  of  the  winged  indi- 
vidual bears  no  secondary  rhinaries, 
while  the  corresponding  organ  of  Pern- 
phigus  tessellatus  is  provided  (accor- 
ding, to  P  erg  an  de)  with  5  —  7 
secondary  rhinaries  (cf.  Fig.  1  and  3). 
The  antennae  cf  the  apterous  forms  of 
the  Transbaicaiian  species  (Fig.  2) 
differ  from  those  of  the  P.  tessellatus 
in  the  third  joint  being  comparatively 
long.  Therefore  I  regard  the  Trans- 
baicalian form  as  a  new  species,  and 
I  name  it  Pemphigus  balcalensis  sp.  n, 
Concerning  the  life  cycle  of  the 
Transbaicalian  Alder  Pemphigus  it  is 
rather  difficult  to  judge  of  it  on  the 
ground  of  the  very  insufficient  infor- 
mation. It  is  even  impossible  to  say  whether  a  migration  exists  or  no. 
As  apterous  individuals  of  different  ages,  larvae,  nymphs,  skins  of  nymphs 
and  winged  mviduals  all  at  once  have  been  found  on  the  Alder  leaf,  it  is 
evident  that  the  winged  Aphides  might  not  have  come  from  without,  but 
were  hatched  even  here  on  the  leaf.  These  facts  seems  to  be  rather  an  - 
argument  against  the  migration.  In  any  case  the  life  cycle  of  the  P.  Ъаіса-  : 
lensis  must  be  different  from  that  of  the  P.  tessellatus,  since  the  generations 
of  the  latter  sucking  on  the  Alder  do  not  live  on  the  leaves  but  on  the  bark  , 
of  the  twigs  and  stems. 
Fig,  4,  Apterous  viviparous  PemjpJiigus  tessel- 
latus Fitch  and  antenna,  magnified.  After 
P  erg  and  e-. 
