70 KANSAS UNIVERSITY SCIENCE BULLETIN. 



Pleural sclerites. — One-half of vertex and corresponding 

 gena. These probably represent lateral elements of sternum, 

 because they enclose the ocular sclerite, which represents the 

 appendage of this segment. 



Appendages. Ocular sclerite. 



2. Deutocerebral or Antennal. 



Tergal sclerites. — No trace. 



Sternal sclerites. — Clypeus. Formed from portion of pro- 

 cephalon, the central swelling of the cephalic end of the body 

 of embryo insects. It is not the first segment nor does it con- 

 tain the mouth, which falls in the tritocerebral segment, but is 

 between the front and the mouth ; therefore, it is a sclerite of 

 the second segment. 



Pleural sclerites. — Antennal sclerites. Lateral elements of 

 sternite, because the antennae arise from them. Even when an- 

 tennae seem to be postoral the basal part of the rudiment of the 

 antennal sclerite appears to abutt against the procephalon. 



Appetidages. — Antennae. 



3. Tritocerebral or Second Antennal. 



Tergal sclerites. — No traces. 



Sternal sclerites. — Labrum. Formed from procephalon; 

 contains mouth, which is in third segment. 



Pleural sclerites. — None determined. 



Appendages. — Second antennae, when found. 



i. Mandibular. 



Tergal sclerites. — Occiput. Continuation of the postgenae 

 which form the pleural sclerites. Packard considers this as 

 belonging to the sixth or labial segment, but as far as my ob- 

 servations have gone I agree with Comstock. It seems to me 

 to be a continuation of the postgenae, which Packard also con- 

 siders as belonging to the mandibular segment. 



Sternal sclerites. — Pharyngeal sclerites. Found in the floor 

 of the mouth cavity of Melanoplus on each side just behind the 

 superlinguae. They are back of the superlinguse, which shows 

 that they must precede superlingual sclerites in the course of 

 the invagination of the mouth. They are also closely con- 

 nected with the mandible. Since in this region sclerites are 

 frequently developed secondarily, Comstock does not think 



