The first genal spine, or first tooth in the head-comb, is shorter in the dog-fleas of both sexes than it is in the cat-fleas.
genal bristles: Diptera; are on the cheeks near lower corner of eye.
The latter are occasionally continued beyond the ocular tubercle back to the genal angle.
Length of cephalon, 40 mm.; width at genal angles, restored, about 62 mm.
genal cca occur on blind trilobites, on trilobites with simple eyes, and on trilobites with compound eyes.
Eye-lines occur on trilobites with both simple and compound eyes, and genal cca may or may not be present in both cases.
We divide the face into three zones: the genal,4 buccal, and frontal.
In all these the genal cca fade out in the genal angles, and in none of them would compound eyes be expected in that region.
The coincidence of the eye-lines with the trunks of the genal cca in Ptychoparia seems to be merely a coincidence.
The relation of the genal cca to the ocelli on the cheeks is best shown in the Trinucleid.
gena ge·na (jē'nə)
n. pl. ge·nae (-nē)
The cheek or lateral side of the face.