Cogswell 1949 Retrochelidon pyrrhonota Aug. 9 Big Lagoon, Humboldt Co., Calif. one observed among numbers of swallows flying over fields (wet pasture) just SE of the lagoon. This species is definitely the least common of the swallows noted here. Aug. 22 2½ mi. NW Schoolhouse Creek, 2300 ft., Humboldt Co., Calif. of this species 10, or more, were among the swallows & swifts flying over grain & stubble fields here. No connection with any ranch buildings was evident. Aug. 30 Willow Creek, 400 ft., Humboldt Co., Calif. one individual was seen as it flew over in southward direction.