368 HYMENOPTERA OF AMERICA. [PART I. 



Gem PTEROCHILUS Klug. 

 Pterochilus Klug. ; Latr. ; Say ; Sauss. 



Buccal parts elongate. 



Labium very much elongate; palpi very large, thick, and 

 much elongate, composed of three joints, of which the first is 

 swelled at the extremity; the 2d and 3d strongly compressed 

 and bipectinate, with very long piiosity ; the 3d joint very 

 elongate. — Maxillary palpi normal, composed of six joints. — 

 Mandibles large, elongate, trenchant, in the form of a knife 

 blade ; the internal edge trenchant, lobed, or notched ; the 

 external edge ciliated with long hair. — Clypeus wide, often 

 lozenge-shaped or trapezoidal, more or less transverse. — Thorax 

 rounded anteriorly and posteriorly, globular or ovate. — Abdomen 

 ovate, depressed, the first segment cup-shaped, subsessile. — 

 Antennae of the males terminated by a hook or by a curved 

 spiral. 



These insects have much the same appearance as the Epipona, 

 but they are very distinct by the extraordinarily large labial 

 palpi, which are feathery, with very long hair. 



The American species belong to the group of PL phaleratus and 

 biglumis, characterized by their .indented mandibles and rounded 

 metathorax. 



1. Pt. I,ewisii Cressox. — Validus, niger, fulvo-pubescens ; clypeo, 

 antennis basi, capitis maculis, pronoti macula subalari, maculis 2 

 scutelli et 2 raetauoti pedibu^que ferrugineis ; tegnlis et post-scutello 

 flavescentibus ; abdominis segmeutis 1°, 20 rufis, basi nigris. omnibus 

 flavo-limbatis ; alis inquinatis. 



Pterochilus Lewisii Cressox, Amer, Entom. Trans., I, 1867, 382, 25, <?. 



Total lengtb, 8.5 lin. 



9. Robus.t ; head and thorax clothed with a pale fulvous 

 pubescence ; abdomen silvery-sericeous in certain lights. Head 

 black, densely punctured ; posterior orbits broadly, anterior 

 orbits narrowly, from the emargination down, the clypeus entirely, 

 the mandibles, except the tips and base and low T er margin 



