1968] 
Matthews — Microstigmus 
33 
quiring from 4 to 36 seconds each (average, 8.5 seconds). During 
another hour, 22 trips were made, ranging from 4 to 50 seconds 
(average, 11 seconds). Apparently both sexes participate in this be- 
havior, and on occasion two or three individuals came outside almost 
Fig. 5. Underside of a Crysophila leaflet and attached nest; note oval 
area from which nest material has been scraped. (About natural size.) 
(Photo by C. W. Rettenmeyer.) 
