The members of the genus Oryssus are appareutly rare in Canada, and I was therefore much pleased to capture on the 2nd June a fine ♀ O. sayi. It was running up and down a telegraph pole (one of the new ones put up for the electric light wires), and had at first glance all the appearance of some small wasp (Crabrolidæ), searching for a suitable hole for its nest. Its movements were very quick, and its antennæ vibrated rapidly. It was so alert and restless that my prospects of capturing it without a net seemed far from bright. However, the capture was made, and its struggles in my cyanide bottle were brief. A few days later I took a ♂ upon one of the same poles, although in a different part of the city, and saw what appeared to be another of these insects fly away from higher up the pole. On the 24th I secured another female, which was even more active than the first, and which flew away and returned to the same place twice before I effected its capture. This habit of flying away when disturbed and of returning, even from some distance, to the very spot left, is one which I have noticed in other species of Uroceridæ.