Chelidon erythrogaster. L.= Baltimore. 1897, Lake Umbagog. May 10: 11 13 Bettle 11 30 Bettue to Upton. " 11 12 30 13 15 14 15 16 17 18 19 20 12 " 21 22 24 25 26 200+ 27 50+ 29 30 " 28 100+ June 9 m(moi's Rock/ 13 Bettue to Upton near Baltimore " Great Island 13 Mr. Chandler shewed me a Barn Swallow's nest built under the frieze of the hotel at Baltimore nearly one the front steps & not 15 ft. from the first door. The bird was sitting. She did not move when we stepped closely beneath her (the nest is about 8 ft. above the floor) & Chandler says that someone yesterday fired upwards of fifty shots from a rifle on a crack as they sat on the frieze nearly under the nest without apparently disturbing the bird. The nest has been there for years. What kind of bird originally built it is not known to C. but it was occupied two years ago by a Robin! Last year no bird made use of it. 15 On watching this nest for about an hour this morning I found that the parents stood the duties of incubation. The change which took place on an average of every fifteen minutes was effected with singular adroitness, the sitting bird slipping off and taking flight at the precise instant that its mate's head reached the edge of the nest so that the eggs would not have been left uncovered for more than a fraction of a second. The wearing bird, tumbling loosely, flew directly to the nest always aiming for those points where its partner's tail projected over the rim. Just as it reached it the sitting bird slipped out on the opposite edge. So quickly was it done that I doubt if a person looking down on the nest from above could have got more than the couple possible glimpse of the eggs. 34