226 CRABRONIDE. 
tured, the petiole very long, slightly curved, smooth above, and 
shining, the extreme margin of the four last segments rufo- 
piceous ¢. 
The ¢ differs in having the antennz compressed, the first 
joint very large and fulvous, as well as the underside of the re- 
mainder, and the fifth, sixth, and seventh also above, the eighth, 
ninth, and tenth serrated below ; the mandibles yellow, with their 
apex rufescent ; the anterior and intermediate legs yellow, with a 
black line beneath the femora, the anterior tarsi yellow, the in- 
termediate ferruginous, with the first joint produced on the ex- 
terior into two curved spiny processes, the apical one bifid, 
and the three following joints also slightly produced at their 
apex on the exterior, the posterior pair piceous. 
g in the Cabinet of the Entomological 
Society, and of Mr. Stephens. 
g in my own and other Cabinets. 
+4+ The Fabrician synonymes certainly refer to this in- 
sect, although Van der Linden rejects the two first, be- 
cause Fabricius says his Pelopeus unicolor is less than 
Panzer’s Crabro unicolor. Van der Linden must therefore 
have forgotten that the latter is the Pemphredon lugubris, 
than which the Psen ater, although the largest of the 
genus, is certainly smaller. Panzer says positively that 
his and Fabricius’ Sphex atra are the same insect (I pre- 
sume he means the opposite sexes), and quotes the latter 
under the new name of Pelopeus unicolor, which Fabri- 
cius gives it in his ‘ Systema Piezatorum,’ with the exclu- 
sion of the reference to his Sphex unicolor. Some doubt 
attaches to the reference to Fabricius’ Trypoxylon atratum, 
for Panzer cites it as the other sex of his Sphezx pallipes, 
which is always smaller than even the smallest red Psen 
(Mimesa); but as Fabricius says it is larger than his Try- 
poxylon equestris (my Mimesa eq.), 1 admit it as a probable 
