TRACHEATA 323 



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- 

 poimd eyes. 



Appendages of Mdolcfidha, 



1. Antennae. 5. 1st pair of legs, prothoracic. 



2. Mandibles, without a palp. 6. 2nd ,, mesothoracic. 



3. 1st maxillae. 7. 3rd ,, metathoracio. 



4. 2nd ,, = 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 labrum, which overhangs the 

 mouth. On each side of this orifice lies 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 ; 



^ Fig. 185. — View of the posterior surface of tlie head of 



Mdolontha vulga/ris. After Strauss-Durokheim. 



1. Eyes. 



2. Opening into head for oesophagus, nerve cord, etc. , to 

 pass, through. 



3. Base of the cut-off antennae. 



4. 1st maxillae. 



5. Maxillary palp. 



6. Labrum. 



7. Labium (= fused second maxillae). 



8. Labial palp. 



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 lacinia, 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 labium. This consists of a mentum and suh- 

 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 jpro-, meso-, and meta-thoraxc ; each of them carries on 

 its ventral surface a pair of legs. The anterior pair are 

 directed forward and the two posterior backward. Each leg 

 consists of the following segments, a coxa, a trochanter, a.Jemur, 



