priests of Mars, of which there were twelve, corresponding to the twelve ancilia or shields of which they had the care, were instituted by Numa, and wore parti-coloured garments and high bonnets, with a steel cuirass on the breast. They were called salii, from saliare, to dance; because, after assisting at sacrifices, they danced along the streets, with bucklers in their left hand and a rod in their right, with which they struck on one another's bucklers, and sang hymns in honour of the gods.