sketch it would seem that the back part of the head, _i.e._ of the epicranium, may be made up in part of the tergite or pleurites of the mandibular segment, since the mandibular muscles are inserted on the roof of the head behind the eyes. It is this labial segment which in Corydalus evidently forms the occiput, and of which in most other insects there is no trace in larval or adult life, unless we except certain Orthoptera (Locusta), and the larva of the Dyticidæ. The following table is designed to show the number and succession of the segments of the head, with their respective segments. TABULAR VIEW OF THE SEGMENTS, PIECES (SCLERITES), AND APPENDAGES OF THE HEAD ═══════════════════════════════╤═══════════════════╤═══════════════════ NAME OF SEGMENT │ PIECES OR REGIONS │ APPENDAGES, ETC. │OF THE HEAD-CAPSULE│ ───────────┬───────────────────┼───────────────────┼─────────────────── │1. Ocellar │Epicranium, │Compound and simple _Preoral_, │ (Protocerebral). │ anterior region │ eyes (Ocelli). in early │ │ with the clypeus │ embryo. │ │ labrum, and │ │ │ epipharynx. │ │ │ │ _Postoral_,│2. Antennal │Epicranium, │Antennæ. in early │ (Deutocerebral). │ including the │ embryo. │ │ antennal sockets.│ │ │ │ │3. Premandibular, │Wanting in │Premandibular │ or intercalary │ postembryonic │ appendages (in │ (Tritocerebral). │ life, except in │ Campodea). │ │ Campodea. │ │ │ │ │4. Mandibular. │Epicranium behind │Mandibles. │ │ the antennæ, │ │ │ genæ. │ │ │ │ │5. 1st Maxillary. │Epicranium, hinder │1st Maxillæ. │ │ edge? Tentorium. │ │ │ │ │6. 2d Maxillary, or│Occiput. │2d Maxillæ or │ labial. │ │ Labium. │ │ │ Post-gula, gula, │ │ │ submentum, │ │ │ mentum, │ │ │ hypopharynx │ │ │ (lingua, ligula), │ │ │ paraglossæ, │ │ │ spinneret. ───────────┴───────────────────┴───────────────────┴─────────────────── [Illustration: