The antenna usually lies in an antennal groove. Some authors
call it also the antennal fossa. The antenna is composed of
three segments, the first, the second and the club of the
antenna. The club is composed of 9 individual segments, in
some species several of those segments can be fused together
The eye of the flea is mostly nothing more than a chitin-layered
protuberance. ESEM pictures suggest, that there is superficially
no compound eye structure retained.
It is the palp bearing lobe of the maxilla. The whole maxilla
actually includes the maxillary palps, the maxillary lacinia
[sometimes also called maxillary stylet], the epipharynx and
the labial palp.
Palps: 3 to 5 segmented [taxonomical importance]
part of the maxilla.
Process: The genal process is a posterior prolongation
of the head, which may or may not narrow to a sharp tip. Sometimes
the structure is more ventrally or posteriorly elongated,
in which case it is referred to as genal lobe.
The frons is the frontal part of the head. Many authors also
include in this term a structure called clypeus. It is only
visible in light microscopy [inside structure] and is a portion
of the anterior part of the frons, where the cibarial dilatator
muscles are attached.
This term denotes the posterior part of the head [see
also head, integricipit/ fracticipit]