1st pair of Jaws

(Mandibles).

2nd  "

(Maxillæ).

3rd  "

(Labium, or 2nd pair of Maxillæ).

Fig. 19.—Diagram of Cock­roach Jaws, in hori­zon­tal sec­tion.

The mandible is undivided in all, or nearly all, Insects. Each maxilla may consist of