617. Stelgidopferyx serriponiis. 5 1/2 inches. In this species the throat is gray as well as the breast. The cuter vane of the outer primary is stiff and bristly, thus giving the species its name. These birds breed from the Gulf north to Massachusetts and Washington, in banks or in crevices of stone bridges. The eggs cannot with certainty be distinguished from those of the Bank Swallow. They measure .75 x .52.