R.K. Selander, 1954 5a C. chiapensis 5.4 mi. NW Tonalá', Chis., Mexico March 20 Collected a Petrona pustulatus in same area when we found cortus wrens. Gave specimen to Landa in trade for a C. chiapensis which one of his boys collected a short distance from camp. Landa also prepared another C. chiapensis collected a short distance from camp. He now has two skins of this species. Chiapensis males show some enlargement of their testes but those of humilis are of minimum size. In late afternoon we watched the group of chiapensis which have been frequenting the area of our camp since we arrived. I believe that there are 4 birds present. At least 3 were seen foraging on the ground and in the branches of a low, dead teach. Singing stops in mid-day but we heard several clut songs in the latter part of the after- noon. Most singing occur in the morning. Noted one bird in a pile of dead branches was complete in the afternoon a few minutes before dark. Note the following incomplete ossification in skull of # 1758. (chiapensis) Two hard, clear areas in the skull.