NORTH AMERICAN HYMENOPTERA. 139 



in group cQ)ifliie)i.tns, Flagellum of S with the first four joints 

 strongly contracted basally and produced at apex, the first and fourth 

 joints most strongly ; fore femora ( % ) beneath at the base somewhat 

 enlarged, the fore tarsi are strongly flattened and broadened, the 

 first joint of medial tarsi variable in length and shape, but never 

 sinuous. 



5. Crabro iiioutanus ('ress. 



Cntbro montanus Cresson, Proc. Ent. Soc. Phila., iv, p. 484, f • 



Crabro cristatuS Packard, ibid, vi, p. 101, % . 



Crabro cuhiceps Packard (non Tascli.), ibid. p. 105, 9 • 



Crabro effosus Provanclier (non Pack.), Hym. Quebec, p. (J60, % (non J). 



9 . — Space between eyes at base of clypeus about equal to the combined length 

 of joints of joints 1 and 2 of the flagellum ; pronotuni sharply margined ante- 

 riorly, distinctly furrowed in a transverse manner, with a rather large, sharp 

 lateral tooth ; dorsulum tolerably strongly striato-punctate on anterior portion, 

 posteriorly with separated punctures; scutellum sparsely punctured, striated behind, 

 mesopleurje rather strongly striated ; upper surface of middle segment separated 

 from the posterior face by a tolerably strong ridge, with strong, somewhat irreg- 

 ular, but tolerably longitudinal, strife, the medial furrow not broad, posterior face 

 finely punctured, apically with some coarse, transverse strise, not ridged laterally, 

 sides delicately striated ; abdomen very finely punctured, the second ventral seg- 

 ment with large, sparse punctures. Black ; mandibles basally, more or less, 

 greater part of scape, sometimes entirely, two spots on pronotum, tubercles, scu- 

 tellum and metanotum in part very rarely, a small spot at tip of fore and medial 

 femora sometimes, tibiae externally more or less, and a spot at each side of dorsal 

 abdominal segments 1-5, yellow or whitish yellow, the si>ots on segment 1 very 

 small and sometimes wanting, those on segment 2 largest, those on segment 5 more 

 rounded and never uniting; tarsi black or dark testaceous. Length 7-10 mm. 



% . — Head rather strongly and closely punctured, the space between the eyes at 

 base of clypeus greater than in the 9 , but not greater than the combined length 

 of flagellum joints 1 and 2, as those joints are longer in the ^ than in the : 

 space between hind ocelli distiu'itly less than that between them and nearest eye- 

 margin ; head strongly margined posteriorly ; pronotum large, very strongly 

 crested anteriorly, the lateral tooth large and sharp ; dorsulum coarsely rugose, 

 irregularly so on anterior portion, longitudinally posteriorly ; middle segment 

 more coarsely sculptured above than in the 9 • the posterior face coarsely trans- 

 versely striated throughout, the sides coarsely striated also ; first joint of medial 

 tarsi shorter than the three following joints united, distinctly dilated a little 

 beyond the middle, but again narrowed to apex, second joint strongly curved and 

 produced at apex within; abdomen somewhat more distinctly punctured than in 

 the 9 ; colored and marked as in that sex, but difiering in the following points : 

 metanotum yellow, fore femora with a yellow streak posteriorly, anteriorly more 

 or less reddish yellow, markings of the abdomen larger, more approximate, the 

 fifth and sixth segments banded. Length 6-7 mm. 



Canada to New York; Illinois; Michigan (Davis); South Da- 

 kota ( Aldrich} ; Colorado ; Nevada ; Mt. Hood, Oregon ; Washing- 



TRANS. AM. ENT. SOC. XXII. M.A.Y, 1895. 



