29 May 5 half-finished. Heard one or two other wrens singing. At a point 16 mi. before Totolapan we found a few pairs of humilis along the stream just off the road and collected several common trees. On hillsides the broad-leafed vegetation is low & widely spaced - probably poor wren habitat. Along the river flat there is a line of trees, guanacbe, minora (?) which form a thicker vegetation type. In general the ecological situation is similar to that at Totolapan (which we had photographed on way downto Chiapas). 5 mi. before Totolapan the road climbs thru hills with dry desert vegetation consisting of cardono-type candelabra-type cacti of huge size, low bushes and very few trees. Trees are mostly very coarse broad-leaf - not much acacia-like type trees - none is some places. A much drier, lower, more open vegetation type than the below. 11mi. beyond Totolapan the road climbs up onto hills where there is a low deciduous forest in leaf. From here on to Oaxaca i go drive thru wide valleys with deciduous forest, often very sparse - no more desert - which ended abruptly 11 mi. beyond Totolepa. Near Mitla we took a picture - then drove to Mitla - and visited the ruins. Most of the area - and the whole Oaxaca Valley region is in cultivation. we saw no habitat in which we could expect to find C. jocosis - but Lamb has collected this species.