XX. TRYPOXYLON. LB AE 
not possess this character. St. Fargeau’s may therefore be 
either another species or a rubbed specimen. Linné’s de- 
scription of its habits is also correct, which is shown above, 
and that it “ nidum argilla claudit” is proved by what I 
shall mention lower down; but Bergman must certainly 
have been placed in a remarkable situation to observe it in 
its cells, “* gue primo purgat circumroditque, deinde fundum 
argilla obducit.” The following anecdote proves also that 
it is not confined to one kind of prey. Mr. Johnson has 
detected it frequenting the holes of a post preoccupied by 
a species of Odynerus, and into which it conveyed a small 
round ball, or pellet, containing about fifty individuals of a 
species of Aphis; this the Odynerus, upon her return, in- 
variably turned out, flying out with it, held by her legs, to 
the distance of about a foot from the aperture of her cell, 
where she hovered a moment and then let it fall; and this 
was constantly the case until the Zrypoxylon had sufficient 
time to mortar up the orifice of the hole, and the Odynerus 
was then entirely excluded ; for although she would return 
to the spot repeatedly she never endeavoured to force the 
entrance, but flew off to seek another hole elsewhere: this 
circumstance leads me to suspect that when the Odynerz 
burrow in wood they do not form their own cells, otherwise 
instinct would have led it to make a forcible entry. Previous 
to having detected the Zrypoxylon with its prey I suspected 
this circumstance might refer to the Pemphredon lugubris, 
which I know to provide its larvee with Aphides ; but Mr. 
Johnson assured me it was a Trypoxylon. 
Sp. 2. aurtFrons. N. Sp. 
atrum, aureo-sericeum, antennis fulvis, abdominis segmentorum 
marginibus ferrugineis &. 
length 7 lines, 
