322 
of  which  the  1st  is  very  small  ;  the  2nd  is  enormously  expanded  at 
the  sides ,  and  the  last ,  which  doubtless  represents  the  dorsal  elements 
of  more  than  one  true  segment ,  also  much  enlarged ,  expanded  late- 
rally and  posteriorly,  so  as  to  entirely  cover  the  anal  region.  —  The 
anus  is  protected  laterally  and  above  and  more  or  less  below  by 
horny  plates ,  but  the  anal  valves  and  sternite  are  not  completely  em- 
braced by  a  ring-like  last  segment  of  the  body.  A  typical  body  seg- 
ment consists  of  a  vaulted  semi-circular  tergite,  constituting  the 
dorsal  plate,  and  a  flattened  ventral  surface,  upon  each  side  of  which 
there  is  a  single  pleural  scute,  the  middle  of  the  lower  surface  being 
occupied  by  a  soft  membrane,  to  which  the  six-jointed,  contiguous 
legs  are  articulated;  there  are  for  the  most  part  two  legs  on  each 
side  to  each  pleura  and  between  the  pleurae  and  the  basal  segment 
of  the  legs  there  are  two  freely  movable  tracheal  plates  or  pedal  la- 
minae, one  corresponding  to  each  leg. 
The  terga  are  not  furnished  with  repugnatorial  pores,  nor  are 
there  setae  corresponding  to  the  position  of  the  pores. 
The  legs  of  the  7th  segment  are  unmodified  in  the  $  ;  but  the  last 
or  last  two  pairs  in  this  sex  are  transformed  into  an  organ  of  copu- 
lation. 
Family  GLOMEBIDAE  (s.  s.). 
Glomeridia,  Brandt,  Bull.  Mose.  1833,  p.  194. 
Antennae  relatively  close  together  on  the  anterior  surface  of  the 
head;  eyes  consisting  of  a  lateral  vertical  series  of  ocelli;  between  the 
eyes  and  the  joint  of  the  antennae  their  is  a  conspicuous  horse-shoe 
shaped  (sensory)  organ. 
Gnathochilarium  with  the  men  turn  and  lingua  distinct,  the  latter 
narrowed  distally;  the  cardo  small,  the  stipes  twice  as  long  as  the 
cardo  and  furnished  with  two  malae. 
Twelve  (rarely  eleven)  distinct  tergal  plates ,  and  on  each  side  ten  pleu- 
rae supporting  the  ambulatory  limbs  ;  the  pleura  of  the  2»d  segment  pre- 
sent, that  of  the  1st  obsolete,  the  anterior  four  terga  with  a  pair  of  legs 
each,  the  5th  to  the  10th  with  two  pairs,  the  11th  with  one  pair; 
the  12th  (the  anal),  representing  apparently  two  segments,  without 
legs  in  the  9,  but  provided  with  two  pairs  (copulatory)  in  the  cf- 
(?  The  last  segment  apodous  its  pleurae  transformed  into  the  anal 
valves.) 
