86 KANSAS UNIVERSITY SCIENCE BULLETIN. 



of the head can be seen, namely : Epicranium, clypeus, and 

 lorse. (Fig. 35, pi. XI.) 



The Epicranium, in the generalized insect, is the dorsal 

 part of the head lying back of an inverted Y-shaped suture 

 (Comstock and Kochi). In this family the suture is clearly 

 marked, the main suture branching at the top of the clypeus 

 and the arms of the suture formed by the lateral edges of the 

 clypeus. The top of the epicranium is almost flat, although 

 there is a slight indentation at the suture and the line curves 

 down slightly to meet the compound eyes. In dorsal view 

 (fig. 1, pi. V) the epicranium narrows from front to back, 

 rolling gently backward and then dropping suddenly to the 

 occiput (fig. 40, pi. XII). The vertex of the epicranium is 

 just back of the suture between the head and prothorax. 



The compound eyes are considered the outgrowth of the 

 epicranium, and are situated at the extreme lateral edges of 

 the sclerite. They are large and globular and composed of 

 thousands of hexagonal facets. As the ventral surface of the 

 eye contains approximately as many facets and is as large in 

 area as the cephalic surface, it would seem that the downward 

 vision of the insect would equal its forward vision. (Fig. 35 

 at c, and 37a at c, pi. XI.) 



Ocelli. — Situated in the front of the head, in an unsutured 

 division of the epicranium, named the Frons, and nearer the 

 clypeus than the vertex, lying either side of the epicranial 

 suture, are the brilliant little ocelli. (Figs. 35 and 37a at a, 

 pi. XL) 



LOR^. Separated by no apparent suture, but nevertheless 

 a division of the epicranium, are the lorse. Their lateral edges 

 extend from the base of the compound eyes to the ventral point 

 of the lateral edge of the clypeus. This division line is about 

 midway of the lateral edge of the clypeus in an oblique line 

 upward to the base of the compound eye. There is thus formed 

 a small triangle with two long and one short side, the short 

 side being next to the clypeus. (Fig. 35 at I, pi. XI.) 



Clypeus.* This sclerite has been discussed and pointed out 

 by the foregoing descriptions until it needs very little ex- 

 planation. In this cephalic aspect it is triangular and with a 

 curved base, the apex of the triangle at the epicranial suture. 



* In the nomenclature of the mouth parts the author follows Muir & Kershaw (2S) 

 in that slie considers what many systematists call frons, clypeus and lahrum, respectivel/ 

 the clypeus, labrum and epipharynx. 



