branch: biology of KANSAS MEMBRACID^. 85 



withstanding the occurrence of two heavy frosts. On Novem- 

 ber 1 several nymphs and adults were found on a food-plant 

 stalk which had been taken to the laboratory for search of 

 egg masses. No evidence of the theory that the form passes 

 the winter in the egg stage has been ascertainable up to this 

 date. 



Morphology. 



■ EXTERNAL ANATOMY. 



Head. 



The head of a membracid is arranged in two planes; one 

 vertical and parallel with the transverse planes of the body of 

 the insect, the other set at an angle of about 95 degrees, or 

 little more than a right angle, to the vertical plane. (Fig. 38a, 

 pi. XI.) 



This vertical plane (which is continued by the cephalic face 

 of the metopidium), when viewed in cephalic aspect, appears 

 as an isosceles triangle. The suture between the head and the 

 metopidium of the prothorax forms the base, and the globular 

 eyes form the equal angles. The ventral edge of the face, 

 which is formed by the clypeus, is the vertex of the triangle; 

 the sides of the lorse extend from clypeus to compound eye, 

 and form the sides of the triangle. (See fig. 62, pi. XVI.) 



Before the head can be viewed in its entirety the prothorax 

 must be removed, as the top of the head is concealed by the prse- 

 scutum. The suture, although in an approximately straight 

 line, slopes slightly downward toward the sides, thus giving 

 the base of the metopidium a curved appearance. (See fig. 62, 

 pi. XVI.) This suture is not articulate in the adult forms, 

 and although easily opened, care must be taken in removing 

 the prothorax, as there are tiny arms produced from the front 

 of the lateral angles of prothorax, which surround the head 

 back of the compound eyes. Frequently, if these arms are not 

 first broken away, the head will pull off' with the prothorax. 

 These arms extend almost around the union of the head with 

 the thorax, and reach to the coxae of the prothoracic legs, to 

 which the arms are attached by a delicate membrane. (Fig. 

 34, pi. X.) The prothorax removed, the head or cephalic 

 aspect thereof can be viewed. This ventral plane is flat when 

 viewed laterally, but is really curved slightly backward on the 

 sides, the middle of the curve being the central line dividing 

 the face into bilateral halves. In this aspect three divisions 



