43a (42a). Compound eyes large and usually contiguous; body somewhat cylindrical, with

thorax arched; ocelli present; middle and hind coxae often with styli; abdominal styli (=

bristlelike processes) on segments 2-9 (Fig.A)..............................................…….....Microcoryphia

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A

43b. Compound eyes small and widely separated or absent; body somewhat flattened

dorsoventrally, thorax not arched; ocelli present or absent; middle and hind coxae without styli;

abdominal segments 1-6 (sometimes 7) without styli (Fig.A) [silverfish] ….....……..Thysanura

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A