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is broader behind. The middle part is almost flat, only very little 
raised towards the' abdoméen, while it slopes laterally towards the 
almost perpendicular sides which bear rounded flat projections twice 
as long ås broåd above the first three pairs of the coxae; the first 
pair is placed” somewhat higher than the second and this again 
higher than the third pair. 
There åre two oblong: eyes on each side placed between the 
median line and the sides and just as near to the front as to the 
back margin of the head. Their longitudinal axes form an obtuse 
angle with each other. 
The abdomen is twice as long as the cephalothorax and broadest 
at the middle. It is raised towards the middle, the highest part 
being mearer the front margin than the anal hill and consequently 
sloping more gradually backwards. The back of the abdomen is 
gradually curved from one side to the: other, while the ventral side 
is flat. On the back side the abdomen is divided into ten tergites, 
distinguished from each other by grooves, distinct in front but more 
or less wiped out behind, and by two pair of muscular spots,. the 
hindmost of which are the most distinct (pl. IV fig. 1 & 2m). The 
muscular spots are corresponding to longitudinal bands of muscles. 
The inner row of spots is the most distinct; behind they are 
merging with' eåch other into one single median spot. In many 
Acari it is difficult to make out if the. dorsal grooves really cor- 
respond to the segments, but in this case the longitudinal bands 
of musceles- put the ségmentation beyond all doubt. The body is 
terminated by the anal hill, placed somewhat obliquely, more ven- 
trally than dorsally. It is divided into a right and a left part, its 
distal part being often more or less invaginated. This anal hill 
must be regarded as the last (XI) abdominal segment. 
The common opinion that the Acari are not at all segmented 
is not .completely correct as shown by Kramer and other acarologs. 
Kramer has proved that A/icus roseus Koch has an abdomen com- 
posed of seven segments (Kramer. 9 pag. 180). The development 
of the segments in the Zarsonemidae is yet more singulår. The 
