Humerus is a bone of forelimbs. It is characterized by the presence of deltoid ridge. Head of the humerus articulate with glenoid cavity of the pectoral girdle. Femur, tibia and fibula are bones of legs. Femur is the longest bone of the body. Its upper end has a rounded head, a constricted neck and a greater trochanter. Tibia is longer, thicker and lies more medially and front. Fibula is shorter, thinner and located more laterally and deeply.