Pectoral girdle : The pectoral girdle is formed of two halves. Each half consists of a clavicle and a scapula .
1. Scapula is a large triangular flat bone situated in the dorsal part of the thorax between the second and the seventh ribs. The dorsal, flat, triangular body of scapula has a slightly elevated ridge called the spine which projects as a flat, expanded process called the acromion. Below the acromion is a depression called the glenoid cavity which articulates with the head of the humerus to form the shoulder joint.
2. Clavicle is collar bone. It is a slender bone with two curvatures.