Vol. xxiii] ENTOMOLOGICAL NEWS. 259 
As in Anthophora occidentalis, some of the tunnels were 
not adorned with a clay device. It seems to us more rational 
to consider these semi-tubes more for protection against pre- 
daceous insects or parasites (as Bombyliid flies, which we do 
not imagine would as readily discover the lateral entrance to 
the Melitoma burrow as they would an unprotected face tun- 
nel), than for shelter against moisture. The Hymenoptera 
of the plains are very much subject to the attacks of parasites. 
The fact that some clay tubes constructed by Hymenoptera, 
notably Odynerus, are often quite vertical would not favor 
the “protection against moisture theory,’ though they would 
offer considerable relief against dust and sand. 
Anthophora occidentalis Cresson. 
Anthophora occidentalis, the “Larger Tube-Building Cliff 
Bee,” is a stout-bodied solitary bee found in large colonies in- 
habiting clay cliffs. Their tunnels are three-eighths inch in di- 
ameter and extend into the bank about eight inches where they 
end in several cells. These cells are provisioned with pollen 
and are so made that when dug out they came from the gallery 
as separate urn-shaped clay nodules of uniform size. (Pl. XV, 
tig 3). 
The entrance of the tunnel is protected by a curved clay tube 
of from three-fourths to two inches in length. (PI. XV, figs. 1 
& 2). These tubes bend downwards and very often the top 
or outer curve is split longitudinally, (probably sun cracked) 
making the tube resemble the moulted skin of a Cicada as it 
hangs on a tree trunk. Where the tubes were absent from the 
tunnels, as was often the case, it appeared to be a matter of 
accident. Viewing the face of a cliff in which there was a 
colony of these bees, the unprotected holes were the only 
marks of its presence, the ones protected by the tubes being 
not at all conspicuous. This may or may not be the reason for 
the tubes. 
As to the life history of these bees, each female has her 
own burrow. The egg is laid in a cell provisioned with pollen. 
We found larvae and pupae in cells, June 20th. It was in colo- 
