Data from the literature on hindlimb muscle variation in birds were gathered with the following goals: 1. to attempt a phylogenetic analysis for all birds, and to tabulate the available data on hindlimb musculature and evaluate the limits of its resolution and its usefulness toward that phylogenetic end; 2. to create a data base that can serve as a guide to other anatomists wishing to use or generate myological data for phylogenetic or other comparative studies; 3. to assess the extent of information available on avian hindlimb musculature, review the work published since a compilation done more than two decades ago, and thereby identify which avian groups are most in need of study; 4. to make hindlimb muscle data available towards the formulation of phylogenetic hypotheses based on a large body of data from a variety of character systems, not just limb musculature. Miscellaneous Publications No. 179.