364 EXTERNAL ANATOMY OF INSECTS. 
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?, 
4. VERTEX (the Vertex). The horizontal part of the Fa- 
cies, next the front, that lies behind the eyes and 
between the temples®. This also is often the region 
of the Stemmata. 
5. Occrpur (the Occiput). The back part of the head 
when it is vertical, or nearly so, to its point of junc- 
tion with the trunk*.—Ex. Meloe, Ripiphorus, 
Hymenoptera, Diptera. 
6. Genz (the Cheeks). Those parts which lie on the 
outside of the anderior half of the eyes, and inter- 
vene also between them and the Mandibule4. 
7. Trmpora (the Temples). Those parts which lie on 
the outside of the posterior half of the eyes, between 
which the Frons and Vertex intervene®. 
8. Ocuxi (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‘. 
A. Cantuus (the Canthus). A process of the face, which 
enters the notch or sinus of the eye?.—Ex. The 
petalocerous and capricorn-beetles. 
* Prats VI. c. _> Tbid. d. “ Tbid. e. 4 bid. f. 
° Ibid. g. f Prares VI. VII. and XXVI. h. 
8 Prare VI, Vic. 1. and VII. Fic. 2. h’. 
