The  form  is  less  regularly  cylindrical  than  in  the  next  tribe ;
the  head  is  usually  very  retractile  and  deflexed,  so  as  to  be  not
visible  from  above,  in  a  state  of  repose,  and  the  eyes  are  in  con-
tact with  the  anterior  margin  of  the  thorax.
Four  sub-groups  may  be  formed,  thus; —

Head  received  in  repose  upon  the  under  surfaces  of  the  prothorax  (Group

Anobia).  2.
Mandibles  in  repose  resting  upon  the  mesosternum  (Group  Xyletini).    3.
2.  Head  free  ;  prothorax  not  excavated  beneath.  Dbyopiiili.
Head  received  in  excavation  of  prothorax.  Akobia.
3.  Antennae  received  in  excavations  on  the  under  surface  of  the  head.
Xylbtiki.
Antennas  received  between  the  front  coxse.  Dobcatom ata.
Sub-Group  1. — D  r  t  o  p  h  i  l  i.
In  these  species  the  body  is  elongate,  the  head  capable  of  being
only  moderately  deflexed :  the  prothorax  not  excavated  beneath
tor  the  reception  of  the  head,  and  the  legs  not  received  in  cavities.
The  antennoe  are  11-jointed,  with  the  last  three  joints  broader,
and  sometimes  very  much  elongated ;  in  repose  they  rest  loosely
upon  the  front  coxae.  The  anterior  aperture  of  the  prothorax  is
circular,  and  the  lateral  margin  is  distinct  in  our  genera,  which
are: —


224  COLEOPl^ESA   OF   NORTH   AMEBIC  A.
Front  ooxae  separated  by  prostemum.  2.
Front  oox»  conical,  contiguous,  prominent.  Emobiw.
2.  Prostemum  moderate ;  tarsi  narrow.  Osognathiui.
Prostemum  very  short ;  tarsi  broad.  Xestobium.
These  genera  are  represented  on  both. sides  of  the  continent.
Ozognathus  cornutus,  bred  from  oak  galls  in  California,  is  re-
markable by  the  mandibles  of  the  %  being  provided  at  base  with
a  long,  slender,  curved  horn,  which,  at  tip,  meets  its  fellow  of  the
opposite  side.
Sub-Group  2. — A  k  o  b  i  a.
