160 WILLIAM J. FOX. 



cheeks; win^s pale fusco-hyaline, paler basally, a dark cloud at apex of marginal 

 cell. Lenoth 13-16 mm. 



% . — Head greatly narrowed posteriorly, deeply excavated in front, finely ]innc- 

 tured above, not or indistinctly striated ; pronotum narrower than the occipital 

 margin of the head, broadly but not deeply furrowed on each side, strongly den- 

 tate laterally : middle segment more coarsely sculptured than in the 9 > coarsely 

 and irregularly rugose above ; fore femora with a long, spine beneath, which 

 points backward, the fore tarsi flattened but not broadened ; no yellow on scutel- 

 lum; fore femora and tibiic entirely, medial femora above, base of middle tibite 

 on outer side, hind tibiae except apex, yellow ; abdomen .spotted as in the 9 > ''"t 

 an additional spot sometimes on the seventh segment laterally ; cheeks beneath, 

 fore femora and niesosternum with long, rather dense, white hair; form slender. 

 Length 9-14 mm. 



Canada; Maine; New Hampshire; Massachusetts; Connecticut; 

 New Jersey ; Pennsylvania ; Ijouisiana ; Illinois. C. quadrangu- 

 laris seems to differ only in its larger size, and C. 14->naci(latm in 

 having two additional spots on abdomen. As the size and number of 

 spots are variable I place tliese two species as synonyms of singularis. 



33. Crabro trapezoifleiis Pack. 



Cmbro trapesoideuts Packard, 1. c, p. 89, % . 

 %. — Head above rather coarsely striato-punctate, not as long or narrowed as 

 much posteriorly as in the % of singularis; pronotum strongly furrowed on each 

 side, as broad as the occipital margin of the head, the lateral tooth not well de- 

 veloped ; striae of mesopleurse and sides of middle segment closer and somewhat 

 coarser than in the species mentioned above, the middle segment above and behind 

 coarsely rugose ; fore legs as in singularis. Black ; mandibles, except tips, scape 

 entirely, pedicellum in part, pronotum almost entirely, tubercles, scutellura ante- 

 riorly, fore legs entirely, medial legs (except the coxse, trochanters, base of femora 

 beneath and apical joints of tarsi), hind femora above, tibise except apex, and 

 first joint of tarsi, and a spot on each side of abdominal segments 2-6, yellow; 

 dense, white hair on the cheeks beneath, mesosternum and fore femora ; wings 

 subhyaline, but little darker apically, darkest in marginal cell and beyond. 

 Length 11 mm. 



Illinois. Resembles closely the % of dngularis, hut is distinguished 

 by the coarse striation of head above, form of j^ronotum and spotted 

 scutellura. Appears to be rare, as I have only seen the unique type. 



34. Crabro aciculatus Prov. 



Cmbro aciculatus Provaucher, Hym. Quebec, p. 664, 9 % • 

 9 . — Head shorter and more transverse than in 9 singularis, finely and more 

 closely punctured ; space between eyes at base of clypeus somewhat less than the 

 width of the latter in the middle; first joint of flagellum distinctly shorter than 

 the two following united, but little longer than the second joint ; pronotum not 

 strongly furrowed, not dentate laterally, transversely striated ; meso- and meta- 

 pleuriB coarsely striated, the sides of the middle segment, however, smooth, or 

 else indistinctly striated, above with longitudinal strife, between which are punc- 

 tures, posterior face transversely striated, particularly on apical portion, the lateral 



