At Pennyfield Lock this a.m., from 6:45 to 9 a.m., I saw, in addition to the common residents, the following mixed bag: chimney swift 10; yellow-billed cuckoo 1; eastern wood-pewee 1; eastern phoebe 3; brown creeper 1; MARSH WREN 1 (in shrubby wetland in wildlife management area); ruby-crowned kinglet 1; blue-headed vireo 1; red-eyed vireo 2; black-throated green warbler 8; yellow-rumped warbler 40 or so; Am. redstart 1; Nashville warbler 1; northern waterthrush 1; magnolia warbler 2; blackpoll warbler 3; common yellowthroat 1; rose-breasted grosbeak 4; indigo bunting 5 Howard Youth hmyouth@erols.com Rockville, MD