Transactions Texas Academy of Science. 
57 
rival at 10 :00 the next morning she had been doing a little dig- 
ging. At 10 :30 she came up to the entrance waving her long an- 
tennae at me and looked out. She then protruded her whole head, 
examined the weather and slowly crawled forth. Soon another 
individual was running around/evidently getting ready for the 
day’s hunt. This one was, however, destined to be shortlived, for 
she ventured too near a spider’s nest, whose owner, a perfect mimic 
of the sand, was lying in ambush. Quick as a flash the spider was 
upon the wasp, gave it a bite and as quickly returned to its lair. 
The wasp collapsed in the same instant. 
At 11:15 the first individual which I had been watching and 
which had returned into the nest, now came forth and, after mak- 
ing a locality study, was off. 
As a storm was approaching, I captured the wasp on her next 
return, eighteen minutes later and dug up the nest. I found it to 
extend downward in a gentle slope for a distance of twelve inches 
to a chamber of one-half inch in diameter. The chamber contained 
seven leaf-hoppers but no egg. 
Alyson oppositus is also common. It is somewhat smaller than 
A. melleus and shows its consanguinity to this species by the small 
round dot on each side of its abdomen as well as by its actions while 
on the hunt. 
(e) Rhopolum (Crabro) Abdominale (Fox). 
This wasp is rather abundant in August and September. The 
sexes can be readily distinguished as they fly around the low vege- 
tation of the woods. The males have but one color, being wholly 
black, while the abdomen of the females is bright red in color. 
The thorax is very broad, which makes the abdomen, tapering grad- 
ually toward the pedicle as in the case of Trypoxylon , look very 
narrow. R. abdominale reminds me of Trypoxylon more than any 
other wasp in the manner of its flight, for both, while out hunting, 
are almost constantly on the wing and have a way of displaying 
their curiosity by touching with their antennas every- leaf or stick 
or blade of grass in their path. 
Like Diodontus americanus , so well described by the Peckhams, 
abdominale has the habit of flying into her open door- way. It was 
this which first called my attention to her on September 14. The 
entrance to the wasp’s nest was a tiny hole in the middle of a small 
flat elevation in the sand. The wasp approached the nest from 
various sides, but whatever direction she came from, she first took 
up a position directly opposite the entrance to her nest, where she 
