THEODORE H. PRISON 139 



every indication that the same state of affairs existed in 1918. 

 The chiy Imnk in which the bees made their homes was about 

 three feet high, two to three feet wide and twelve feet long. It 

 was situated but a short distance from the river beneath a steel 

 bridge connecting with the opposite bank and beside one of the 

 concrete foundations supporting the structure. Here the bank 

 was in a semi-protected situation, but still at times exposed to 

 the glare of the sun and rain blown about by the wind. To all 

 appearances, the clay bank was simply a pile of clay removed 

 by workmen when engaged in excavating for the concrete 

 foundation pillars of the bridge. The clay was the same as 

 that found anywhere along the river and any num])er of situa- 

 tions possessing about the same qualifications might have been 

 selected by these mining bees. 



Besides the colony just mentioned I found another one of the 

 same species in the same year. This also was at Oakwood, 

 Illinois, but on the opposite side of the river and about an 

 eighth of a mile from the first colony. It is interesting to note 

 that again I located the colony by following the flight of the 

 bees returning to their homes after collecting water at the river 

 bank for their mining operations. When I first came upon the 

 bees going and coming from the moist sand near the river's 

 edge, I knew by reason of previous experience the significance 

 of this and immediately looked about for the site of the colony. 

 This happened to be the precipitous clay wall of the river bank, 

 not far from where the bees were obtaining their water supply. 

 The colony was situated just l^elow a large tree growing on the 

 very brink of the almost perpendicular clay wall. Here, in the 

 clay more compactly held together by the major root system 

 of the tree, the bees had made their l)urrows. The colony was 

 only about one-fifth the size of the one under the bridge and so 

 hard of access that I made no further study of it. 



When speaking of the situations selected by Anthophora 

 ahrupta for their mining operations it is interesting to note 

 what other authors have to say concerning this species and 

 certain other Anthophorinae. Walsh found this species making 

 burrows in the mortar between joints in brick work and also in 

 "the face of a precipitous clay bank." Riley says this same 



TRANS. AM. ENT. SOC, XLVIII. 



