Ecological and Behavior Notes 31 



that two females were nidificating in the same hole; 

 rather it would seem more likely that a second one had 

 merely come in to spend the night. The discovery at this 

 late hour of the day proves conclusively that these wasps 

 do not go elsewhere to spend the night. 



The burrrow was about eight inches in depth and of 

 the contour illustrated. (Plate VIII fig. 12, half natural 

 size). The width varied from about three-eights to one- 

 half inch. The form of this nest differed considerably 

 from that of the one described in Wasp Studies Afield, 

 p. 127. 



Cerceris flavofasciata H. S. Sm. [S. A. Bohwer]. 

 Taken on buck-brush flowers at Weseo, August 1, 1920. 



Omalus iridescens Norton. [S. A. Rohwer]. A sumao 

 twig was taten at Meramec Highlands on July 6, 1918. 

 Early in August a cuckoo-bee emerged. The following 

 April a second individual of this species emerged, show- 

 ing an astonishingly wide difference in the time of matur- 

 ity, or at least of emerging. The remains of chewed-up 

 pith in this twig pointed to Ceratina calcarata as the 

 host. 



Chrysis (Tetrachrysis) venusta Cress. [S. A. Rohwer], 

 A dead specimen was found in an elder stem, October 

 15, 1918. 



BEES 



Halictus lcrou<rii Lep. [J. C. Crawford]. A male was 

 found feeding on the flowers of sweet clover on July 19, 

 1918, and on buck-brush on August 1, 1920. 



Halictus lign<itus Say. [J. C. Crawford]. For half an 

 hour I watched one individual which was sitting motion- 

 less within its burrow looking out, with its face flush with 

 the surface of the ground, and fitting the hole like a plug. 

 When finally it was routed and the burrow explored, a 

 second one was found within. This was on July 25, 1915. 



Halictus parallelus Say. [S. A. Rohwer]. A number 

 of these bees were seen on the flowers of wild aster near 

 the river at Wickes as late as October 13, 1920. Others 



