548 
Cantharis  Vesicatoria. 
/Am.  Jour.  Pharro. 
X  November,  1898. 
large  and  conical,  entirely  concealed  by  the  elytra,  which  not  only 
project  beyond  the  posterior  portion,  but  also  cover  the  sides,  which  is 
characteristic  of  the  blistering  beetles.  The  blistering  beetles  are 
well  represented  in  this  country,  and  it  is  to  be  regretted  that  they 
have  not  a  place  in  the  U.  S.  Pharmacopoeia,  as  they  are  in  no  wise 
inferior  to  the  C.  vesicatoria  in  vesicating  properties.  The  most 
common  are  C.  vitatta,  C.  cineria,  C.  margiiiati,  C.  atrata,  and  C 
vulnerata.  The  best  known  is  C.  vitatta  (Fig.  j),  commonly  called 
potato  fly.  It  is  somewhat  smaller  than  C.  vesicatoria,  being  from 
y2  to  inch  in  length  and  about  T3g  inch  in  breadth.  It  is  of  a  black 
color,  with  the  exception  of  ochreous  markings;  the  under  portion 
of  the  body  is  cinereous ;  head  cordate  of  a  light  ochre  color,  with 
two  black  spots  on  the  apex;  mandibles  entirely  concealed  by  the 
labrum ;  labial  palpi  two-jointed,  the  last  joint  large  and  flattened; 
maxillary  palpi  three-jointed  ;  antennae  black  and  filiform  ;  clypeus 
large;  eyes  large  and  compound,  extending  over  the  lower  side  of 
the  head;  prothorax  elongated  and  much  narrower  than  the  head, 
of  a  black  color,  with  a  brownish  yellow  central  and  a  faint 
lateral  line;  coxae  of  the  first  pair  of  legs  much  elongated;  the 
articulated  portion  of  the  femora  are  of  an  ochre  color;  the  other 
portions  are  cinereous;  scutellum  small;  elytra  are  black,  with  a 
median  and  marginal  stripe  of  yellow;  they  slightly  overlap  the 
pleurites.    The  whole  insect  is  covered  with  a  fine  pubescence. 
The  vesicating  properties  of  the  blistering  beetles  reside  in  a  crys- 
tallizable  substance  termed  cantharidin,and  according  to  some  writers, 
Fig.  3.— Cantharis  Vitatta. 
