5 mi. N Tehuacán, 1676m. May 26 on the hillside I found the wrens evenly spread in similar sized groups. Within these groups there is some evidence of pairing in that pairs are frequently seen flying about & calling. I collected several birds. When surrounded one bird went down a rockent hole at the base of an agave. There are few agaves in this area and most - perhaps all - appear to have been planted by former inhabitants of the rather numerous huts in the flat areas. In general these birds are wary and their behavior recalls that of lemniscapillus. In the low desert vegetation they frequent all levels, from the ground, where they feed not infrequently, to the tops of the yuccas. Calling generally takes place from the top of a tene or mosquito hut but they call also from a dense thicket while they are concealed from view. Their flights are short & direct; rarely exceeding 30-40 yds. and mostly much shorter as they prefer to work thru the vegetation rather than to fly over it. The do not call frequently and after once calling they are likely to remain silent for some time. The white in the tail is conspicuous in flight as the tail feathers are somewhat fanned out. The resemblance to lemniscapillus is sometimes striking when the birds are seen in the costros and mosquito. Like that species they are difficult to hunt in open situations. In the tule trees they occur at all levels from