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Fig. 179.—Abdomen of Machilis maritima, ♀, seen from beneath: the left half of the 8th ventral plate removed; I-IX, abdominal segments; c, cercopoda; cb, coxal glands; hs, coxal stylets; lr, ovipositor.—After Oudemans, from Lang.

The cercopoda.

They are very long and multiarticulate in the Thysanura (Fig. 179). In the Dermaptera they are not jointed and are forcep-like. It should also be observed that in the larva or Sisyra (Fig. 181) there are seven pairs of 5–jointed abdominal appendages, though these may be secondary structures or tracheal gills. In the Perlidæ and the Plectoptera (Ephemeridæ), they are very long, sometimes over twice as long as the body, and composed of upward of 55 joints; they also occur in the Panorpidæ (Fig. 177). In the dragon-flies the cerci are large, but not articulated, and serve as claspers or are leaf-like^[35] (Fig. 180). In a few Coleoptera, as the palm-weevil (Rhynchophorus phœnicis), Cerambyx, Drilus, etc., the so-called ovipositor ends in a hairy, 1–jointed, palpiform cercus. Short 25–jointed cercopoda are present in Termitidæ, and 2–jointed ones in Embiidæ.