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(i) Ornithodoros .—Note the deep sulci (Fig. ioo), 
especially 
1. The supra-coxal groove, which gives rise to 
the supra-coxal fold and extends quite around the 
anterior portion of the body. 
2. The pre-anal sulcus, lying just in front of the 
anus and very conspicuous in sections. 
Fig. ioo. Ornithodoros : (i) side view, (2) dorsal view, 
(3) ventral view 
3. The sulci about the head. The conical head 
can be retracted to a considerable extent into the fold 
of the integument (camerostome). 
At the base of this fold is a groove, and in it the 
opening of the cephalic gland. This opening can be 
seen by forcibly flexing the head on to the belly. 
On the coxae of the first pair of legs, lying within 
the groove which separates this from the coxa of the 
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