R.K. Selander, 1952 Tern sp.? = Chlidonias niger August 21 Pie de la Cuesta, 20ft., Guerrero, Mexico - one small tern (about size of S. hirundo but smaller, thinner, more delicate) over the laguna. Noted thick blackish line through eye. August 24 One tern (same as above in appearance) over laguna. August 25 "Montosa" Island, sea level, Laguna Coyuca, Guerrero, Mexico - Common in laguna, especially about the island. Groups of 10 or more birds seen at various times; probably over 30 different individuals seen during trip from Pie de la Cuesta to the island. A specimen taken which I have tentatively identified as C. niger. I believe this specimen is same species as that I have observed on Aug. 21 and 24. - There may be another species of tern here, however. Aug. 26 Pie de la Cuesta, 20ft., Guerrero, Mexico - 7 sw ant over laguna (sea level).