AMERICAN ENTOMOLOGY. 91 



POMPILUS. Plate XLII. 



Generic character. Labrum inserted under the nasus ; eyes 

 entire ; stemmata three ; antennae as long as the head and trunk, 

 in the female convoluted towards the tip ; mandibles unarmed, 

 or with one or two teeth j maxilliary palpi longer than the 

 labials, three last joints nearly of equal length ; superior wings 

 not folded longitudinally ; radial cellule of moderate size ; cubital 

 cellules three, the first elongated ; second and third subequal, 

 nearly square, receiving the two recurrent nervures ; fourth cell- 

 ule rudimental ; feet elongated. 



Obs. These insects associate by pairs, and make their nests in 

 the earth. The female digs a hole in a sunny bank or declivity ; 

 when this is accomplished, she goes in search of a spider or a 

 catapillar, which she punctures with her sting, and places at the 

 bottom of her nest. Having deposited an egg, either in or upon 

 the prey, she closes the hole with earth, and abandons it. The 

 young, hatched from the egg, has an abundant and convenient 

 supply of food, in the body of the interred insect. Descending 

 the Arkansaw river, with Major Long's party, I was one day 

 surprised to see a species of this genus, dragging along the 

 ground the body of the gigantic Bird-catching spider, the Mygale 

 avicularia, or a very closely allied species. 



These insects are lively and active, flying rapidly from place to 

 place for short distances, running briskly on the earth, vibrating 

 their antennae, and raising a little, and then depressing their 

 wings, which are reclined upon the back. 



The female is armed with a sting, and may be distinguished 

 from the male by having twelve joints to the antenna^ whilst 

 those of the male have thirteen joints. 



Latreille was the first to separate this group from Sphex, under 

 the name of Psammochares, but in his subsequent works, he 

 adopted the more recent name of Pompilus, given by Fabricius. 



Pompilus FORMOSUS. — Specific character. Polished bluish- 

 green ; wings rufous, with a dusky terminal submargin. 



Pompilus formosus nobis, Western Quarterly Reporter, ii. p. 76. 



Desc. Body bright greenish, a little tinged with bluish, and 

 in some lights changing to dull purplish, sericeous : antennae 

 black : feet black with a green reflection : wings bright golden 



