INDIVIDUAL VARIATION.--In three legs the nerve supplying M. extensor iliotibialis anticus gives twigs into M. extensor iliotibialis lateralis. In another leg one of the branches to the fused Mm. vastus lateralis and vastus medialis sends a twig into M. extensor iliotibialis lateralis. [Illustration: FIG. 17. _Tympanuchus pallidicinctus_ 2L. Lateral view of the muscles of the left leg. The following muscles, in addition to those listed for Fig. 16, have been removed: vastus lateralis pars postica, gluteus profundus, flexor cruris medialis (in part), caudofemoralis, flexor perforatus digiti IV, and tibialis anticus. × 1.] _P. p. jamesi_ [Illustration: FIG. 18. _Tympanuchus pallidicinctus_ 2L. Lateral view of the muscles of the left leg. The following muscles, in addition to those listed for Fig. 17, have been removed: patellar tendon, iliacus, iliotrochantericus medius, flexor cruris lateralis, flexor cruris medialis, flexor ischiofemoralis, adductor superficialis, femorocruralis, gastrocnemius pars media, flexor perforatus digiti III, flexor perforatus digiti II, flexor hallucis longus, plantaris, flexor digitorum longus, popliteus, and extensor digitorum longus. × 1.] DIFFERENCES FROM TYPICAL _T. pallidicinctus_.--The posteroproximal aponeurosis is more extensive, resulting in a narrower proximal fleshy end (fig. 20G); the fleshy fibers adjacent to this aponeurosis are not overlapped by M. flexor cruris lateralis. There is a fusion of fibers between the anterodistal fleshy part of M. extensor iliotibialis lateralis and the underlying M. vastus medialis, but there is no fusion of fibers between the anterior edge of M. extensor iliotibialis lateralis and M. extensor iliotibialis anticus. The connective tissue binding the posteroproximal corner to adjacent muscles is stronger. The fleshy part of the origin is narrower, partly tendinous, and much thinner (reflected in a thin lateral iliac process). The proximal border is much more nearly straight, owing to a less pronounced lateral iliac process. The distal accessory aponeurosis is absent. [Illustration: FIG. 19. _Tympanuchus pallidicinctus_ 2L. A. Posterior view of the muscles of the left shank. The following shank muscles, in addition to those listed for Fig. 17, have been removed: gastrocnemius pars media, flexor perforatus digiti III, and flexor perforatus digiti II. × 1. B. Posterior view of the proximal end of the shank, showing the most deeply situated muscle. × 1. C. Lateral view of the head of the left femur and the middle part of the pelvis, showing the deepest part of M. obturator. × 1. D. Medial view of the posteroventral part of the left side of the pelvis, showing the intrapelvic part of M. obturator. × 1. E. Anterior view of the left tarsometatarsus, showing the dorsal intrinsic muscles of the foot. × 1-1/2. F. Posterior view of the left tarsometatarsus, showing the ventral intrinsic muscles of the foot. × 1-1/2.]