CE?) 
seldom quits the ground, rapidly skipping along, which 
makes it difficult to capture. The inferior wings are ge- 
nerally narrower than the superior, but in the male Astata 
boops they are wider. The flight of this insect also is sin- 
gular. It rapidly makes a wide gyration in the air, and re- 
turns to settle upon the same clod it started from, and this 
it will repeat a dozen times in the course of five minutes. 
It is rarely that these insects, which are so powerfully 
armed, and so very bold, simulate death, upon the ap- 
proach of danger, by closing up their legs and wings and 
falling down; this is however the case frequently in the 
genus Vysson. The .ees are very variously formed; 
they are generally of a moderate length, but in some they 
are very short in proportion to the body, as in: Ziphia, 
Philanthus, Cerceris, Crabro, and very robust in the latter. 
In others (the Pompilide and Sphecide), they are very long 
and adapted for running; in Ceropales, in particular, they are 
disproportionately so. Their tibia are sometimes armed 
with spines, and their anterior tarsi with cilia on the exte- 
rior, and upon this structure, or the absence of it, St. Far- 
geau proposed a theory for the distribution of these insects 
into parasites or non-parasites, but which I have shown 
elsewhere in detail,* that howsoever ingenious it may ap- 
pear, it is nevertheless not correct. In the paper referred 
to, I suggested that it might distribute them into those 
which nidificate in wood or sand, which St. Fargeau seems 
to have adopted, for in a monograph of the genus Crabro,+ 
he says, “‘ La présence ou Vabsence de cils aux tarses ante- 
rieures (ce qui indique que ces insectes travaillent dans la 
terre ou dans le bois ),” and has consequently dropped his 
* See Entomological Transactions, my paper upon the Aculeate Hymenop- 
tera, vol. i. pt. 1, p. 52. ; 
t Annales de la Société Entomologique de France, tom. iil. p. 692. 
c2 
