branch: biology of kansas membracid^. 87 



The ventral edge is densely hirsute. The whole cephalic face 

 is deeply pitted or punctate and frequently mottled with dark 

 patches. (Fig. 35 at y, pi. XI.) 



The plane at an angle of 95 degrees to this cephalic face 

 is also a triangle, the base being the ventral edge of the ce- 

 phalic face and the apex the distal end of the epipharynx. (See 

 Fig. 37a, pi. XI.) 



In this plane are found the mouth parts proper, and here 

 are situated all the typical sclerites of a suctorial mouth, 

 namely, clypeus, labrum, epipharynx, mandibular and maxil- 

 lary sclerites with their respective setae, and the labium or 

 beak. 



Situated also in this plane are the gense or cheeks, and the 

 antennal sockets with the delicate antennae. The compound 

 eyes are also visible in this plane. When at rest the beak lies 

 between the coxse of the legs of the insect and close to the 

 sternum, but when in use it is lowered onto the food plant by 

 special muscles. 



The GENiE (fig. 37a at g, pi. XI) are irregular quadrangu- 

 lar plates surrounded by the compound eyes, the mandibular 

 and maxillary sclerites and the overhanging lorse. These gense, 

 with the maxillary sclerites, form the lateral edges of this 

 plane of the head. 



Antennal Socket. (Fig. 35 at x, pi. XI.) Situated on 

 the inner edge of the genae, and lying against the ventral face 

 of the clypeus and under the overhanging edge of the lorae, is 

 the circular socket or antennal sclerite, its edge next to the 

 genae being the quadrant of a circle. 



Antenn.^. (Figs. 36 and 37a, pi. XI.) The antennae are 

 pale in color and extremely minute and bristle-like. So minute 

 and delicate are they that they are scarcely discernible with 

 a pocket lens; in fact, they are frequently absent in mounted 

 specimens, as they are easily broken off. 



The antenna, which measures 0.45 mm. in length, is com- 

 posed of three segments — two stout basal segments (to and n, 

 fig. 36, pi. XI) , the second and heavier of which bears sensoria; 

 the third segment is spur-like, having a thickened base and 

 gradually becoming slender until the distal end is hair-like. 

 This spur, although unsegmented, has more than fifty small 

 divisions, the last one much longer than the others. (Fig. 36, 

 X, pi. XI.) The antennae are very deeply set into the socket. 



