N0.H8-. NORTH AMERICAN DIGGER WASPS— FERNALD. 891 



times eleven) comb teeth, the last one or two very stout; their length 

 about half that of the metatarsus. 



Male. — Difiers as follows: The scape is less evidentl}" ferruginous 

 beneath; traces of silver}" pubescence are present on the end of the 

 median segment al)ove the petiole; mesopleuron at the base of the fore 

 wing black; petiole black, sometimes fainth' tinged with ferruginous; 

 abdomen quite whitish-sericeous, this increasing posteriorly and Ijeing 

 very pronounced and coarse on the last three segments; posterior mar- 

 gin of the last dorsal plate evenly rounded; clypeus with a slight 

 depression on the median line anterior to the middle; seventh ventral 

 abdominal plate slightly, broadly emarginate, the eighth less broadly 

 but more deepl}' so; tlie terminal plate (juite strongl}' rounded at the 

 sides, acuminate in the middle behind and with a slight ridge along 

 the middle; wings quite uniformly fuliginous and with a slight violet 

 reflection, but still with a yellowish tinge in some cases; femora 

 partly — the posterior pair mostly — black; the last tarsal segments 

 generally darker than the others, the tips of which are their daVkest 

 portions. 



Variations. — In some specimens variations from these characters 

 have been observed. In one case the pubescence on the cl3'peus and 

 frons was golden below, becoming silvery above, and it extended well 

 above the antennae; the anterior face of the collar was strongly seri- 

 ceous; the scape was nearly all ferruginous; traces of a lateral meso- 

 notal pubescent band, silvery white in color were seen; the dorsum of 

 the median segment was closely covered with short dull yellow erect 

 hairs and the posterior end of the segment was dull j^ellow pubescent; 

 the hinder part of the prothoracic lobe, a vertical streak ])ehind it and a 

 spot or streak above the middle coxse were yellowish-white pubescent. 

 One female had a black petiole, the last three abdominal segments 

 black and the others so dark as to seem dark reddish brown. Other 

 specimens show one or another of these variations. 



Length. — Females, 21-27 mm. ; males, 19-25 mm. 



This species appears to have a somewhat restricted habitat. The 

 specimens seen all came from Texas, New Mexico, Arizona, and Col- 

 orado, the records being: "Tex.; ""Col.; " Florence, Arizona, August 

 23, 1902, and April 20, 1903; Congress Junction (July), and Bill Wil- 

 liams Fork (August), Arizona; Las Cruces, New Mexico; Alamogordo, 

 New Mexico (VI, 7, '02); and Yuma County, Arizona, September, 

 1903. 



In some respects this species resembles Chlorion ruficauduni{Deihl- 

 bom), l)ut difl'ers from it in not having its tibite enlarged near the end, 

 and in having partly yellow legs and in the practical absence of pubes- 

 cence. 



