A RHINARIUM (the _Nostril-piece_). The space between the anterior margin of the _Nasus_ and the _Labrum_, in which, in vertebrate animals, the nostrils are often situated[973].--N. B. _This is remarkable in some Lamellicorn beetles, as_ Anoplognathus _Leach_. _In_ Necrophorus, _and some others, it is membranous_.
2. POSTNASUS (the _Postnasus_). That part of the _Face_ immediately contiguous to the _Antennæ_, that lies behind the _Nasus_, when distinctly marked out.--Ex. _Sagra_, _Prosopis_.
3. FRONS (the _Front_). That part of the _Face_ which lies behind the _Postnasus_, and usually between the posterior part of the eyes. This is sometimes the region of the _Stemmata_; or they are partly in this or partly in the _Vertex_[974].
4. VERTEX (the _Vertex_). The horizontal part of the _Facies_, next the front, that lies behind the eyes and between the temples[975]. This also is often the region of the _Stemmata_.
5. OCCIPUT (the _Occiput_). The back part of the head when it is vertical, or nearly so, to its point of junction with the trunk[976].--Ex. _Meloe_, _Ripiphorus_, _Hymenoptera_, _Diptera_.
6. GENÆ (the _Cheeks_). Those parts which lie on the outside of the anterior half of the eyes, and intervene also between them and the _Mandibulæ_[977].
7. TEMPORA (the _Temples_). Those parts which lie on the outside of the posterior half of the eyes, between which the _Frons_ and _Vertex_ intervene[978].
8. OCULI (the _Eyes_). The principal organs of sight, most commonly two in number, placed in the sides of the head. In the majority they are compound, consisting of hexagonal lenses. In the _Arachnida_ they are simple[979].
A CANTHUS (the _Canthus_). A process of the face, which enters the notch or sinus of the eye[980].--Ex. _Scarabæus_ L., _Cerambyx_ L.
9. STEMMATA (the _Eyelets_). Two, or more commonly three, convex, crystalline, simple eyes, observable in the _Frons_ or _Vertex_, or common to both[981].--Ex. _Orthoptera_, _Hemiptera_, _Hymenoptera_.
10. ANTENNÆ (the _Antennæ_). Two moveable and jointed sensiferous organs, situated in the space between or before the eyes, but in no instance behind them[982]. They include the _Torulus_, _Scapus_, _Pedicellus_, and _Clavola_.
A TORULUS (the _Bed_). The cavity or socket in which the base of the _Antenna_ is planted[983].