[Illustration: FIG. 10. A,B. Semidiagrammatic drawings of the peroneal nerve of _Tympanuchus pallidicinctus_ 1L, showing the distribution of the branches. × 2. C. Semidiagrammatic drawing of the distal part of the peroneal nerve of _Tympanuchus cupido attwateri_ 1R, showing the distribution of the branches. × 2. 1,2, M. tibialis anticus (tibial head); 3,4, M. tibialis anticus (femoral head); 5, M. extensor digitorum longus; 6, nonmuscular; 7,8, M. peroneus longus; 9, M. peroneus brevis; 10,11, M. extensor hallucis longus (proximal head); 12, M. extensor hallucis longus (distal head); 13-15, nonmuscular (to toes); 16, M. abductor digiti II; 17, M. extensor brevis digiti III; 18, M. extensor brevis digiti IV.] [Illustration: FIG. 11. A,B. Semidiagrammatic drawings of the tibial nerve (excluding the paraperoneal branch) of _Tympanuchus pallidicinctus_, showing the distribution of the branches. × 2. A. T.p. 1L. B. T.p. 3R. C. Semidiagrammatic drawing of the distal part of the paraperoneal branch of the tibial nerve of _Pedioecetes phasianellus jamesi_ 2L, showing the distribution of the branches. × 2. 1, M. femorocruralis; 2, M. gastrocnemius pars media; 3, M. popliteus; 4, M. plantaris; 5, M. flexor digitorum longus; 6-8, nonmuscular; 9-11, M. gastrocnemius pars interna; 12,13, M. flexor hallucis longus; 14-16, M. flexor perforatus digiti IV (medial head); 17, M. flexor perforatus digiti III (medial head); 18-20, M. flexor perforatus digiti II; 21, M. flexor perforatus digiti IV (lateral head); 22-24, M. flexor perforatus digiti IV (anterolateral head); 25, M. flexor perforatus digiti III (anterolateral head); 26, M. flexor perforans et perforatus digiti III; 27,28, M. flexor perforans et perforatus digiti II; 29, M. gastrocnemius pars externa; 30,31, M. abductor digiti IV; 32,33, M. flexor hallucis brevis; 34,35, nonmuscular (to toes).] MUSCLES In the accounts of the muscles the name used by Hudson, _et al._ (1959) for each muscle is given in parentheses after the name used by me if the two differ. In the account of each muscle, the description of the condition found in most specimens of the Lesser Prairie Chicken (_T. pallidicinctus_) is given first. This is hereafter referred to as the typical condition for _T. pallidicinctus_. Then any individual variations found within this species are given. Under the heading _T. cupido_ any constant differences between this species and typical _T. pallidicinctus_ are given first, and any individual variations found within the species _T. cupido_ (both subspecies considered together) are given second. Under the heading _P. p. jamesi_ any constant differences between this subspecies and the typical condition for _T. pallidicinctus_ (thus these differences are not necessarily constant between the two genera) are given first, and any individual variations found within the subspecies _P. p. jamesi_ are given second.