History. and Habits of Pityogenes. 29 
of the burrow. When this obstruction was removed with a 
needle he continued onward and found the entrance. After 
examining the brink carefully he plunged in until only the 
end of the elytra protruded from the liquid resin. Appar- 
ently by trying several methods he had succeeded in dispos- 
ing of enough of the pitch so that the end of his abdomen 
would remain unsubmerged and he could resume work. On 
the following day the burrow was still occupied but was little 
if any deeper than when last seen. All of the worker's ef- 
forts seemed to be needed in keeping the hole from closing, 
with his body, and in arranging the hardening pitch into a 
‘chimney ” around the entrance. Four days later the bur- 
row had been carried no deeper and the specimen was found 
dead in the hole embedded in hardened pitch. 
It would appear to be established then that after the bur- 
row is well started, P. hopkinsi will not be driven from it by 
being submerged either in water or in pitch, and that it will 
continue working in either of these, so long as the breathing 
opening between the ends of the elytra and abdomen is not 
covered. When this is covered with water the beetle immedi- 
ately becomes motionless and remains so until this subsides 
below the level of the end of the abdomen. When submerged 
entirely in pitch it attempts to dispose of this in several dif- 
ferent ways. Usually as shown by examination of numer- 
ous burrows in living pine, it is successful, but occasionally 
it is overcome and is smothered in the sticky material. Only 
a very few pitchy burrows have been found which had ap- 
parently been abandoned and there is always the possibility 
that the insect may have been overcome by a _ predaceous 
enemy or that the body may have been removed by a scaven- 
ger after death. In several cases evidence of this was found 
in the form of portions of the head and legs still embedded 
in the hardened resin of apparently abandoned burrows. 
' Construction oF THE Nuptrirat CuamBer.— It has. al- 
ready been shown that by the time the burrow is deep enough 
to cover about half of the body, the burrowing beetle begins 
to widen it somewhat. It is thereafter continued at such an 
angle that when it is completed and the insect in the guard- 
