84 SPHECIDE. 
second cylindrical; the clypeus transverse, convex, truncate 
in front; labrum concealed; mandibles long, narrow, arcuate, 
acuminate at their apex, and dentate within. Tuorax oval; 
the collar transverso-quadrate, narrowing into a kind of neck ; 
’ the suture that separates the dorsolum and scutellum very 
advanced, extending between the tegule of the superior 
wings; the scutedlum semicircular, flat; the metathorax trun- 
cated posteriorly ; the superior wings with one marginal and four 
submarginal cells—the marginal cell long and narrowed beyond 
the second submarginal, the first submarginal having the com- 
- mencement of a nervure springing from the first transverso-cubital 
and returning backwards—the second and third submarginal cells 
much narrowed towards the marginal, and each receiving a re- 
current nervure—the fourth extending to the apex of the wing ; 
the legs long and slender; the core subglobose; the femore 
obclavate, slightly flattened on the interior surface. The 
ABDOMEN Slightly elongate, conical, attached to the thorax by a 
broad, short, flat petiole; the first, second, and third segments 
constricted at their margin; the terminal segment prolonged 
into an obtuse puint, whence the sting is exserted. 
Type, D. corniculus. 
+4 The etymology is 801%, long—oupe, a tail, from the 
prolongation of the apex of the abdomen. It is rather singu- 
lar that Latreille should have given the genus a masculine 
termination, the Greek substantive from which it is derived 
being feminine. The insect which led to its construction had 
been described by Spinola as a Pompilus, but both Latreille 
and Jurine, to whom he sent it upon finding subsequently 
other specimens, considered it immediately a new genus 
allied to Alyson, whence he called it Alyson ater, forgetting, 
I suppose, that he had previously described it as Pomp. 
corniculus ; but I strongly suspect that his A. ater is the 
Pison ater of the continent. The specific name will con- 
sequently remain the same as first described by Spinola. 
