Ventral paired appendages of the thorax.
There are a few phylogenetically informative characters on the femur, tibia, and tarsus. In Desmometopa(Litometopa) and some other Desmometopa species (Sabrosky 1983), the fore legs are raptorial in appearance, with ventral spines on femur, elongated coxa and femur, and in Litometopa also with a striking colour pattern. This shape of the fore legs probably evolved within Desmometopa (after Brake 2000).
Each leg consists of a coxa, trochanter, femur, tibia and tarsus. The structure of these segments differs in the fore leg, mid leg, and hind leg (pro- meso-, and meta-thoracic legs), and all legs sometimes show striking modifications on all segments. The different leg surfaces are ascertained by imagining that all the legs are fully extended laterally, parallel to each other and at right angles to the main axis of the body. Thus each segment of each leg has an anterior, posterior, dorsal, and ventral surface. Other surfaces are named on the same basis, e.g. anterodorsal and posteroventral (ex McAlpine 1981).