192 HYMENOPTEEA. 



hinder ocelli separated from the eyes by a greater distance than they are from each 

 other ; apex of the clypeus truncate ; the extreme apex of the clypeus and the 

 greater part of the mandibles rufous. Pronotum longer than the head, quadrate, the 

 sides straight, the apex transverse. Scutellum wider than long ; the apex rounded. 

 Median segment with the apex oblique, the top rounded, the centre excavated, densely 

 covered with a silvery pubescence. Abdomen shorter than the head and thorax 

 united, shining, subpetiolate, the apex sharply pointed. Legs comparatively short, 

 covered with a silvery pile ; the long spur of the hinder tibiae does not reach the middle 

 of the metatarsus ; the tibiae with some weak spines. The antennae are as long as 

 the thorax, stout; the third joint a little longer than the fourth. The fuscous wings 

 have a lighter cloud running down from the base of the radial cellule, and another 

 proceeds from the base of the second cubital cellule to the apex ; the basal nervure is 

 not interstitial ; in the hind wings the anal nervure is received a long distance in front 

 of the cubital. 



The next species is easily recognized by the apex of the median segment being 

 excavated and projecting laterally as stout teeth, and by the tibiae being without spines, 

 the smaller spur of the hind pair flattened and dilated. 



20. Pompilus sinaloae. 



Long. 9 millim. 



Hab. Mexico, Presidio de Mazatlan (Forrer). 



Black, with a faint bluish tinge ; wings violaceous. Eyes converging beneath ; the 

 hinder ocelli separated from each other by a greater distance than they are from the 

 eyes ; clypeus broadly rounded at the apex. Antennae as long as the head and thorax 

 united, covered with a microscopic pile ; the third joint longer than the fourth. 

 Prothorax as long as the head, arcuate at the apex. The median segment oblique 

 and concave at the apex, the sides projecting above into blunt teeth; there is a 

 depression at the base. Abdomen as long as the thorax ; the apex bare. Legs long, 

 stout ; the tibiae bare ; the claws stout, sub-bifid ; the hind tibial spurs short (about 

 one-fourth the length of the metatarsus), stout, the shorter spur leaf-like ; the anterior 

 spurs longer and sharper. 



Species 21-41 have black or bluish bodies, with fuscous, blackish, bluish, or violaceous 

 wings. From the similarity of their coloration, and from many of the descriptions not 

 making any mention of structural peculiarities, the species are not easily recognized or 

 identified. Many of them vary from black to blue in colour. 



