HOMOPTERA 397 



parts of the head can be distinguished. Figure 462 represents a lateral 



Fig. 462. — Head and prothorax of a Fig. 463. — Head of a cicada, front view: 



cicada, lateral aspect: a, antenna; md, mandibular seta; mx, maxillary 



c, clypeus; e, compound eye; ep, seta; other letters as in Fig. 462. 



epipharynx; /, labrum; 0, ocelli; 2, (After Marlatt, with changes in the 



3, second and third segments of the lettering.) 

 labium. (After Alarlatt, with changes 

 in the lettering.) 



view of the head and prothorax of a cicada, and Figure 463 a front view. 

 The corresponding parts are 

 lettered the same in the two 

 figures. 



The compound eyes 

 (Figs. 462 and 463,^), the an- 

 tennce(Figs. 462 and 463, a), 

 and the three ocelli (Figs. 

 466 and 467,0), can be easily 

 recognized and need not be 

 described in detail. 



The front is a small scle- 

 rite near the summit of the 

 head. It can be most easily 

 recognized by the fact that 

 it bears the median ocellus. 

 In the adult insect the su- 

 ture between it and the ver- 

 tex is indistinct; but in the exuviae of a nymph, where the epicranial 

 suture has been opened by the emergence of the adult, the outline 

 of this sclerite is evident (Fig. 464). In many homopterous insects 

 the front is vestigial or wanting. 



The vertex (Figs. 462 and 463, v) bears the paired ocelli. 



The clypeus (Figs. 462 and 463, c) is very large, occupying the 

 greater part of the anterior surface of the head. In several of the 



Fig. 464. — Part of the exuviaa of the head of 

 a nymph of a cicada: a, antennae; as, 

 antennal sclerite; c, clypeus; e, e, com- 

 pound eyes; /, front; v, v, vertex. (After 

 Berlese.) 



