LIBRARY

22 COLLEGE ENTOMOLOGY
feebly articulating or fixed segment and acts as the pivoting joint; may be single
or divided into two sclerites, the coxal process and the trochantin, and may
rarely also possess an inner sclerite, the antecoxal piece. The subcoxa (precoxa,
pretrochantin) is the single basal segment in certain primitive forms. Stylus
(pI. styli) is a small finger-like appendage on the inner margin of each coxa of
Machilis; also borne on the large ventral abdominal plates or coxites of Machilis
FIG. 12. Head and n1.outh parts of the
European cabbage butterfly, Pieris brassiere
(Linn.), showing the remarkable
curled proboscis or maxillre. (After
Pfurtscheller.)
and Lepisma in the order THYSANURA.
Similar one- or two-segmented organs occur
on the first three abdominal segments
in the order PROTURA.
Trochanter - second division of the leg;
short and simple in most insects or long
and divided into two parts in mature and
immature ODONATA and in larvre of
certain COLEOPTERA and apparently
divided (one part is end of femur) in
parasitic HYMENOPTERA; frequently
triangular, with the femur articulating on
the outer surface; large and somewhat
ovoid in the hind legs of carabid beetles
Femur (pI. femora) or rnerus - third and
in most adult insects the strongest and
most prominent segment; usually somewhat
thickened; those of the hind legs
greatly enlarged in such jumping insects as
grasshoppers, crickets, katydids, beetles,
and fleas.
Tibia (pI. tibi;e) or carpus - fourth division;
usually as long as or longer and
slenderer than the femur; cylindrical or
compressed and dilated posteriorly; outer
margin furnished with spines or swimming
hairs; often modified for capturing and
holding prey, digging in the soil or in wood, swimming and other purposes;
with one or two pairs of movable spurs referred to as middle spurs or ajJical
spurs. Strigilis or antenna cleaner - a large articulated curved comb-like
spur on the inner extremity of the fore tibia opposing a comb of hairs on the
metatarsus in bees. Epiphysis - a strigilis-like spur or pad on the inner extremity
of the fore tibire in certain LEPIDOPTERA.
Tarsus (pI. tarsi) - the extremity of the leg; a single segment in primitive
PROTURA and THYSANURA but comprising one to five segments or rarely
absent in higher orders; the segments cylindrical or broad and pad-like, slender
and long or wide and short; sometimes hairy or spined; metatarsus or basal segment
often much larger than rest and specialized to oppose the strigilis to form
the antenna cleaner on the forelegs and to complete partly the corlJicula or