HYMENOPTERA. 129 
In some the first segment of the thorax forms either a transversal 
or longitudinal square, and the abdomen is attached to the thorax 
by a very short pedicle; the inner side of the posterior tibiz is usually 
furnished witha brush. The superior wings have two or three com- 
plete or closed cubital cells, and another imperfect and terminal. 
They now form several subgenera. 
Pepsis, Fab. 
To which I assign the following characters: labrum apparent; an- 
tennz, at least of the males, almost straight and composed of com- 
pact or crowded joints; maxillary palpi hardly longer than the labial, 
projecting, and formed of but slightly unequal joints; three complete 
cubital cells, and the first recurrent neryure inserted near the ante- 
rior extremity of the second. The tibie and first joint of the pos- 
terior tarsi are compressed in the males. 
All the species known are foreign to Europe, and most abun- 
dant in South America and the Antilles; they are large, and 
have coloured wings(1). 
Crropa.es, Lat. Fab. 
The labrum and antennz of the Pepses; but the maxillary palpi 
are much longer than the labial, pendent, and with very unequal 
joints(2). 
Pompi.us, Fab. 
The Pompili, in this latter respect, resemble the Ceropales, but 
the antenne of both sexes are curled and composed of loose or but 
slightly compact joints; the labrum is concealed or but little exposed. 
According to Fabricius and the more recent systems, we must 
restrict this subgenus to those species in which there are three 
complete cubital cells, neither of them petiolate, the mandibles are 
unidentated on the inner side, and the thorax is slightly or mode- 
rately elongated in comparison with its width. These Insects -lay 
up provisions for their larve, consisting of Araneides, which they 
first put to death with their sting, and then transport to the holes 
destined for the domicil of their young. 
P. viaticus; Sphex viatica, L.; Panz., Faun. Insect. Germ., 
(1) Lat., Gen. Crust. et Insect-, IV, 61. 
(2) Lat., Ibid., 62; Van der Lind., Observ. on the Hymen. of Eur., 76. 
Vou. IV.—R 
