INSERTION.--The short unossified tendon of the anterolateral head and the longer ossified tendon of the medial head join (after the latter becomes flexible) a short distance above the tibial cartilage, forming a broad flat common tendon that passes posterior to the tibial cartilage (in a shallow groove of the latter); the main part of the tendon is deep to the tendons of Mm. flexor perforatus digiti IV and flexor perforans et perforatus digiti III, but forms separate thin sheaths around these two tendons at the level of the tibial cartilage. A thin sheet of connective tissue covers these three tendons and attaches by its edges to the tibial cartilage, forming a sheath for them. These three tendons pass through the superficial groove in the hypotarsus deep to the tendon of M. gastrocnemius; the tendon of M. flexor perforatus digiti III is ossified for most of the length of the tarsometatarsus; a short distance below the hypotarsus, the anterior branch of the tendon of M. peroneus longus attaches broadly to the lateral edge of the tendon of M. flexor perforatus digiti III. In the proximal part of the tarsometatarsus the tendon is deep to the tendon of M. flexor perforans et perforatus digiti III, but farther distally becomes medial and then superficial to the latter and lateral to the tendon of M. flexor perforans et perforatus digiti II; near the distal end of the tarsometatarsus a narrow but strong vinculum extends from the lateral edge of the tendon somewhat distally to the lateral edge of the tendon of M. flexor perforans et perforatus digiti III. At the distal end of the tarsometatarsus the tendon expands before entering the ventral surface of digit III where it soon divides into two branches, between which emerge the tendons of Mm. flexor perforans et perforatus digiti III and flexor digitorum longus; the lateral branch attaches to the subarticular cartilage ventral to the first interphalangeal joint and to the lateral surface of the distal end of the first phalanx; the medial branch has similar attachments on the medial side of the digit. INNERVATION.--The posterior division of the tibial nerve passes between the medial heads of M. flexor perforatus digiti III and M. flexor perforatus digiti IV and sends a twig to the lateral surface of the former, then passes deep to the common belly of M. flexor perforatus digiti IV and sends a twig to the posterior surface of the anterolateral head of M. flexor perforatus digiti III. INDIVIDUAL VARIATION.--None of significance. _T. cupido_ INDIVIDUAL VARIATION.--In one leg, an extra branch (immediately distal to the branch to M. gastrocnemius pars media) of the medial division of the tibial nerve penetrates the medial surface of the proximal end of the medial head. _P. p. jamesi_ INDIVIDUAL VARIATION.--None of significance. =_M. Flexor Perforatus Digiti II_=, Figs. 15, 17 _T. pallidicinctus_