The trochanter is severely reduced in flies homozygous for tsh^md621. The coxa is reduced and lacks most of the bristles and sense organs found in wild-type. The femur is short, but contains the normal complement of proximal sense organs. Although tye trochanter is reduced, joints can still be seen between coxa, trochanter and femur segments. One or two sensilla trichodea are generally found at the articulation between the reduced trochanter and coxa segments (as compared to two groups of 5-7 in wild-type). In tsh^md621/tsh^HD1 flies the trochanter is no longer detectable as a discrete segment and the coxa appears to articulate directly with the femur. Both coxas and femur are reduced in size. No sense organs can be recognised on the coxa and trochanter rudiment, but the sc11 group of campaniform sensillae is reliably found on the proximal femur.