npectoral archthe bony arch formed by the collarbones and shoulder blades in humans
Webster's Revised Unabridged Dictionary
Pectoral arch(Anat) the two or more bony or cartilaginous pieces of the vertebrate skeleton to which the fore limbs are articulated; the shoulder girdle. In man it consists of two bones, the scapula and clavicle, on each side.
Pectoral arch suspended from the skull: no mesocoracoid arch.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 6" by Various