E. Medial view of distal end of M. flexor cruris medialis of _P. p. jamesi_ 4L. × 1. Part of insertion is covered by medial collateral ligament. F,G. Lateral views of posteroproximal corner of M. extensor iliotibialis lateralis (removed from specimen). × 1. F. _T. pallidicinctus_ 2L. G. _P. p. jamesi_ 3L. H,I. Dorsolateral views of M. piriformis. × 1. H. _P. p. jamesi_ 1L. I. _T. cupido attwateri_ 1L. J. Lateral view of M. caudofemoralis pars caudifemoralis (removed from specimen) of _T. c. pinnatus_ 4L. × 1. K. Lateral view of extrapelvic part of M. obturator of _T. pallidicinctus_ 3L (bones not shown). × 2. L,M. Region surrounding obturator foramen of _T. pallidicinctus_ 3L, showing points of attachment of three parts of M. obturator (muscles removed). × 3. L. Lateral view. M. Medial view. N. Anterior view of left tarsometatarsus of _P. p. jamesi_ 4L, showing dorsal intrinsic muscles of foot. × 1-1/2. Tendon of M. extensor digitorum longus has been removed. =_M. Ambiens_=, Figs. 13, 16, 17 _T. pallidicinctus_ GENERAL DESCRIPTION AND RELATIONS.--Thin and elongate; on medial surface of thigh; broadest above middle of belly; belly narrowed distally, forming long slender tendon passing lateral to distal part of M. extensor iliotibialis anticus; bounded anterolaterally by M. vastus medialis and posterolaterally by Mm. femoritibialis internus and psoas (proximally). ORIGIN.--The muscle arises by a short flat tendon from the pectineal process. INSERTION.--The long slender tendon enters an elongate channel within the patellar tendon; the point of entrance is at the proximal end of the latter tendon just medial to the patella; the tendon passes distolaterally (within the channel) below the patella and emerges from the distolateral edge of the patellar tendon and then extends distally along the anterolateral surface of the head of the fibula, superficial to the fibular arm of the guide loop for M. extensor iliofibularis, and joins the anterolateral surface of the common tendon of origin of the anterolateral heads of Mm. flexor perforatus digiti III, flexor perforatus digiti IV, and flexor perforatus digiti II; the point of junction is usually immediately proximal to the proximal end of the lateral head of M. flexor digitorum longus. INNERVATION.--The branch of the middle division of the femoral nerve that supplies M. femoritibialis internus gives off a tiny twig or twigs that penetrate the lateral surface of the proximal part of M. ambiens. INDIVIDUAL VARIATION.--None of significance in _T. pallidicinctus_ or in _P. p. jamesi_; in _T. cupido_ the origin is partly fleshy in one leg. =_M. Vastus Lateralis_= (M. femoritibialis externus + part of M. femoritibialis medius), Figs. 14, 16 Fisher and Goodman (1955) apply the name femoritibialis externus to the muscle unit that I here term the pars postica of M. vastus lateralis. The reasons for this change are discussed in the section on terminology. _T. pallidicinctus_