XVIII. NYSSON. 99 
F. Smith has captured it this year at Hampstead carrying 
off Epeolus variegatus, a little bee which I have myself 
never observed there—this proves that its larva is sup- 
plied with a variety of food. It is difficult to detect the 
g burrowing, for, like Ammophila, she selects a cavity 
already formed, in the interior of which she constructs her 
burrow free from observation. Their flight is extremely 
rapid, and the g settles upon small clods, whence it momen- 
tarily makes wide circumyolations. 
Genus XVIII. Nysson. Latr. 
Heap transverse, about the width of the thorax ; face covered 
with a silvery down; eyes oval, prominent ; stemmata placed 
in a triangle on the vertex, slightly elevated ; antenne inserted 
at the angles of a small elevation at the base of the clypeus, 
generally slightly increasing towards the apex, with the scape 
obconic, the second joint subglobose, and the rest regularly 
increasing in length and thickness from the third to the 
terminal one, which in some ¢ is emarginate, and in others 
seated obliquely upon the penultimate ; the c/ypeus transverse, 
rounded anteriorly, and in some having the margin slightly 
reflexed; labrum concealed; mandibles arcuate, unidentate, 
and acuminate at their apex. The tHorax oval; the collar 
transverse, linear; the scutellum transverse, lower than the 
dorsolum ; and the metathoraz inclining gradually, having a 
spine on each side towards its posterior extremity; superior 
nings nith one marginal and three submarginal cells—the first 
submarginal considerably longer than the other two—the second 
petiolated, and recewing both the recurrent nervures—the third 
forming an elongate hexagon, and distant from the extremity 
of the ning ; the legs moderately long, and very slender, the 
tibie and tarsi densely covered with down. The aBpomMEN 
subsessile, ovoido-conic, and incurved at its extremity, with 
its terminal segment furcate in the ¢ ; the first ventral segment 
plane, the second very much produced in front, and forming 
an obtuse angle. Type, N. spinosus. 
H 2 
