200 p. CAMERON. 



Golden, Colorado ; San Miguel, Colorado (Oslar). 



Except that the base of the first abdominal segment above is 

 roughened, showing an approach to Ancistrocerus, this species 

 agrees fairly well with Hypodernus, which section is rare in the 

 Nearctic region. It is more slenderly built than the typical forms 

 of that group. The sides of the metanotum being margined (but 

 not very strongly), may cause one to refer it to Sanssure's Section 1 

 of Ancistrocerus, with the rugosity on the top of the first abdominal 

 segment. 



The group of fedorensis Cam. {rujinodis Cress.). 



This is a group of small-sized species, with the greater part of 

 the median segment, the basal segment of abdomen and the legs red. 



Note. — There does not appear to be any clear line of demarca- 

 tion between Odynerus s. sir. and Ancistrocerus. The suture may be 

 distinct or merely indicated by the basal slope not being so strongly 

 punctured as the rest. 



The grouping of the species may be regarded as my first attempt 

 to range the species according to their natural afiitiities. 



Oclyu«*rus fedorensis sp. nov. 



Black, the median segment, first abdominal segment and the legs red ; the 

 clypeus, basal half of mandibles, a mark roundly dilated laterally above, under- 

 side of antenna] scape, a broad, interrupted line on the pronotum,a broad curved 

 line across the apex of the seutellum, base, apex and outerside of the tegulse, a 

 large mark, transverse above, rounded below, on the mesopleuraj below the 

 tegulfe, a baud on tlie first and second abdominal segments, that on the second 

 all round, and a large, irregularly rounded mark on the sides of the second abdo- 

 minal segment, yellow; the tarsi are blackish; there is a yellow mark on the 

 apex of the fore femora behind, and the four anterior tibije are yellow in front. 

 Wings hyaline, the radial cellule smoky, the stigma and nervnres fuscous. % . 

 Length to end of second abdominal segment 6 mm. 



First abdominal segment cup-shaped, except at the base, closely strongly punc- 

 tured; the apex distinctly curled up and more strongly punctured; the second 

 segment is closely punctured, more strongly towards the apex, which is more 

 strongly reflexed than the first, its base clearly narrowed. Clypeus broader than 

 long, obliquely narrowed laterally above, coarsely, clo.'sely punctured ; its apex is 

 shortly, bluntly bidentate ; deeply depressed above. Head above closely strongly 

 punctured ; the eye incision thickly covered with silvery pubescence; the space 

 between the hinder ocelli is depressed ; occiput transverse, the temples are longer 

 than the eyes above; there is a small yellow sjiot on them above. Base of thorax 

 transverse, the lateral angles acute. Apex of postscutellum transverse, the apical 

 slope smooth. Apex of metanotum not much excavated, furrowed down the 

 middle; the centre and outer edges punctured, the rest smooth; below, on the 

 sides, is a loiigish sharp spine. Antenna! stout; the apical hook does not reach 

 to the apex of the last joint. The middle of the mandibles is red. Palpi black- 

 ish, as are also the anterior coxa' and trochanters. 



