F08SORE8 — AMPULICID^. 113 



all parts of the country ; it differs from the other genera chiefly by 

 the two-jointed petiole of the abdomen. 



Pelopcens and Chnlybion are closely allied ; the species of the for- 

 mer are black with yellow markings, while those of Chnlybion are 

 blue or violet in color, and with the petiole of the abdomen much 

 shorter. They construct their nests of mud in the corners of rooms, 

 under the roofs of outbuildings and other sheltered situations. 



The sjiecies of Chlorion are large insects, and are among the most 

 beautiful of our hymenoptera, being of a brilliant blue, green or 

 violet color ; the genus is distinguished by the unidentate tarsal 

 claws ; only two species have been described as inhabiting our fauna. 



Podium is represented by two species, both very rare, from the 

 Southern States ; in this genus the form is long and slender, the pro- 

 thorax elongate and narrowed into a neck. 



Isodontia has three species, all originally described as belonging to 

 Sphex, which, however, differs by the much shorter abdominal i)etiole, 

 and different form of the anterior margin of the clypeus. 



Sphex contains twelve species of wide distribution, most of them 

 being large, handsome insects, of strong, vigorous habit. 



Of the other genera, Hmpactopus is represented by three si)ecies 

 from Colorado and Texas, and of Priononyx, which has 5-toothed 

 tarsal claws, three species have been described, two of which are of 

 common occurrence. 



Family AMPULICIDiE. 



Form long and slender; head large, flattened, subtriangular ; clypeus rostrate, 

 the mandibles large, free, acute at tip; antennae slender; prothorax elongate, 

 produced anteriorly into a rather slender neck ; metathorax suhquadrate, 

 truncate posteriorly, the upper surface depressed, longitudinally carinate and 

 reticulate ; wings narrow, rather short, anterior pair banded with fuliginous, 

 two submargiual cells, the first twice as long as the second, and receiving the 

 first recurrent nervure in the middle ; legs long and slender, femora swollen 

 in the middle ; abdomen elongate-ovate, acute at apex, smooth and polished, 

 attached to the thorax by a slender petiole, which is shorter than the jioste- 



rior coxse Rhinopsis Westw. 



This curious genus is represented by a single species, canalicu- 

 LATA Say (Ampulex), West. Quar. Rep. ii, 1823, p. 76 {= pemyf- 

 vanicm Hald., Proc. Acad. Nat. Sci. Phil. 1 ^49, p. 203; = Abbuttii 

 Westw., Arcany Ent. ii, p. 68, pi. 6o, fig. 5), described from Penn- 

 sylvania, Greorgia and Missouri, while the 9 sj)ecimen in the collec- 

 tion of the American Entomological Society is from Canada. It 

 ai)j)ears to be of very rare occurrence. 



TBANS. AMER. ENT. SCO. (15) 8UPPL. VOL. 1887. 



