TRACHEATA 
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number (some thousands) of shallow pits lined by specialised 
sense cells connected with nerves, which apparently function 
as olfactory organs. 
Immediately behind the base of the antennae lie the com- 
pound eyes. 
Appendages of Melolontha, 
1. Antennae. 5. Ist pair of legs, prothoracic. 
2. Mandibles, without a palp. 6. 2nd 5 mesothoracic. 
3. 1st maxillae. 7. 8rd 53 metathoracic. 
45/2nd 5; = Labium. 
The oral appendages comprise the typical insect mouth 
parts, a pair of mandibles, and two pairs of maxillae. The 
anterior part of the head forms the clypeus, and this is con- 
tinued into a hinged portion, the /abrwm, which overhangs the 
mouth. On each side of this orifice les a mandible, a_biting- 
jaw of pyramidal shape, whose opposed edges bear a number 
of teeth. The first pair of maxillae are behind the mandibles ; 
Fic. 185.—View of the posterior surface of the head of 
Melolontha vulgaris. After Strauss-Durckheim. 
1. Eyes. 
Opening into head for oesophagus, nerve cord, ete., to 
pass through. 
Base of the cut-off antennae. 
Ist maxillae. 
Maxillary palp. 
Labrum. 
Labium (=fused second maxillae), 
Labial palp. 
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each consists of a basal piece which articulates with the head, 
the cardo, this bears another joint, the stipes, and the stipes 
terminates in an inner piece with one tooth, the dacinia, and 
an outer piece, the galea, with a row of teeth. A maxillary 
palp is inserted into the distal end of the stipes. The second 
pair of maxillae have fused together and formed a plate-like 
lower lip, the labiwm. ‘This consists of a mentum and sub- 
mentum, and it carries a pair of labial palps. The function of 
both pairs of palps is sensory. 
The thorax is made up of three segments, called respect- 
ively the pro-, meso-, and meta-thorax; each of them carries on 
its ventral surface a pair of legs. The anterior pair are 
directed forward and the two posterior backward. Each lee 
consists of the following segments, a cova, a trochanter, a femur, 
