NORTH AMERICAN HYMEXOPTKRA. 137 



of segment 5, yellow : no yellow on niesopleurse or ventral segments of abdomen ; 

 pubescence of face and clypeus silvery. Wings subhyaline, somewhat darker 

 apically, nei'vures and stigma testaceous. Length 8 11 mm. 



% . —Coarsely sculptured like the female, but more strongly so; fiagellum sub- 

 clavate, not widened basally ; prouotum rather .strongly dentate laterally ; middle 

 segment very coarsely rugose, particularly above, the sides with coarse, more or 

 less irregular striations. Abdomen with one, more rarely with two or three ter- 

 minal bands. Length 8-10 mm. 



Occurs from Canada to Florida Ashiuead); Illinois ; Nebraska 

 ( Barber) ; Colorado ; Montana. Probably our most common species, 

 and subject to .some variation : the spots on pronotum are sometimes 

 wanting and the femora are rarely yellow in greater part. A female 

 specimen from District of Cokunbia (Ashmead) has the pronotum 

 scarcely dentate as in produdicolli^i, but is too coar.sely scidptured 

 for that sjiecies. The smooth bodied specimen mentioned by Packard 

 is evidently a female of prod uctico I ll>i (= 4-macH/atus Prov.). 



3. Crabro be litis Cress. 



Crabru betlns Cressou, Proc. Ent. Soc. Phila., iv, p. 481, f • 

 Crabro atrifrons Cresson, ibid. p. 483, % . 



?. — Head with strpng punctures, those between the ocelli and occiput, how- 

 ever, close and continent, those on tlie front large and S]jarse ; thorax as in inter- 

 rnptus, but a little less coarsely sculptured ; abdomen distinctly punctured, but 

 more finely and closely punctured than in inferruptiis. Black ; .scape, pedicellum, 

 two spots on pronotum, sometimes wanting, tubercles, scutellum and metanotum 

 sometimes (usually black, however), tips of femora more or less, tibije except dark 

 spot internally, tarsi (apical joints darker), a long, narrow spot on each side of 

 dorsal abdominal segments 1 r>, those on segment five nearly always united, and 

 those on segment one sinuous, all yellow ; no yellow on mesopleui-se or ventral 

 segments of abdomen ; pubescence of clypeus silvery ; wings subhyaline, rather 

 strongly tinged with yellow basally, particularly along the costa, nervures and 

 stigma yellowish testaceous. Length 9-11 mm. 



% . — This sex difl'ers from interrnptus in the .same characters as does the J : the 

 finer sculpture and in possessing one or two more terminal bauds on abdomen ; 

 wings darker than in the 9 1 ^"'^ i^^t yellowi-sh ; pronotum with a large tooth 

 laterally. Length 6-8.5 mm. 



Colorado ; Nevada ; Mt. Hood, Oregon ; Washington. Very 

 close to liiterrKptii-f, but more finely sculptured, and the spots on ab- 

 dominal segments 4 and 5, at least on 5, united. The thoi-ax is 

 usually sparsely spotted in both sexes, while in itiferri(pfa.s the usual 

 markings are present ; this is, how'ever, variable in both sjjecies. 

 The width of the clypeal production varies and the medial lobe is 

 often armed with a strong tooth on each side of the medial ])rocess ; 

 this character occurs also in the other species of the grouj) but is less 

 developed. 



TRANS. AM. ENT. SOC. XXII. (18) MAY, 1895. 



