CICADELLINAE : PART I. PROCONIINI 9 



aspect, has long been used as a taxonomic character (these are the 

 "Jochstiicke" of Melichar's classification). In most genera (fig. la), 

 they appear, in lateral aspect, to extend over the line of the lateral 

 clypeal sutures like the crosspiece of a T. Their surface may be convex, 

 concave, flat, sulcate, or foveate, and in lateral aspect they may or 

 may not be angular or carinate dorsally. Their anterior edges may 

 be steep or gradually slanting (oblique) into the contour of the face. 

 The transition from crown to face may be either gradual or abrupt 

 and marked by an angle or carina. 



The cl)q3eus (postclypeus of some autliors) is separated from the 

 clypellus (anteclypeus of some authors) by a transclypeal sulcus which 

 may be distinct throughout its length, or obsolescent medially. The 

 ventral portion of the face is usually pubescent in the Proconiini, the 

 pubescence being conspicuous and often involving the clypellus, a 

 portion of the cl)Tpeus, the lora, and part or all of the genae. The 

 clypeus may be strongly convex, flattened medially, or with a concave 

 area. It usually bears the impressions of the muscles which dilate the 

 cibarium. The contour of the clypellus may be almost a continuation 

 of the profile of the clypeus, or it may be protuberant in profile, with 

 its lower portion almost parallel to the long axis of the body. 



The thorax has several useful characters: Its greatest width compared 

 with the transocular width of the head, the shape of the lateral margins 

 in dorsal aspect (parallel, convergent anteriorly, divergent anteriorly), 

 the sculpturing and pubescence of the disc, the shape of the posterior 

 margin, and the texture of the scutellum. The dorsopleural line of the 

 pro thorax is often (almost always in the Proconiini) carinate (fig. la). 

 The carina may extend from the humeral angle to the eye (complete) 

 or may end some distance behind the eye (incomplete). The proepister- 

 num is never concealed in the Cicadellinae. The form of theproepimeron 

 (fig. la) has been used occasionally in the present classification. In a few 

 genera its posterior margin bears a digitate posterior projection that 

 overlaps the mesepisternum to some extent. In the genus Phera the 

 lower margin of the proepimeron is rather wide and is broadly depressed. 

 The mesepimeron (fig. la) bears a longitudinal or diagonal groove 

 which receives the coastal margin of the forewings when they are in a 

 position of rest. In many museum specimens, the wings do not rest 

 completely in the groove and are not then considered to be in rest 

 position. Because of the degree of angle from the horizontal of the groove 

 and because of the degree of curvature of the costal area of the fore- 

 wing, the wing at rest may conceal or reveal (fig. 1 a) the mcron of the 

 hindleg and even the more dorsally situated metepimeron. This char- 

 acter is of importance in the present classification, although it diflfers in 



260-649—68 2 



