LIBRARY

66
COLLEGE ENTOMOLOGY
pound eyes are large and prominent or vestigial and even tot.ally absent, and
ocelli are present in relatively few forms. The mandibles are slender, entire
or in two parts; the maxillary palpi are composed of four, five, 01' seven
FIG. 26. O>mparative sizes of some species of THYSANURA and APTERA. A, MacMlis
maritima Leach (after Lubbock); B. A.cratelsa collaris Escherich (after Escherich); C. Camp()I}.ea
slaphylinus Westwood (after Lubbock); D. Anajapyx veslclilosus Silvestri (after Imms);
E. Iapyx soljugltS Haliday (after Lubbock).
segments, the incisor and molar areas being wide apart; and the labial palpi
are three-segmented. The thorax forms the widest region of the body. The
legs are similar, and in the machilids there are one or more movable styli or
exopodites on each of the middle and hind coxre. The tarsi are composed of
three or four segments with paired claws. The abdomen is composed of 10