74 Myron Harmon Swenk 



anterior middle of the mesoscutum black). While the third 

 antennal joint may be longer than indicated for morrisoni it is 

 probably not longer than in N. (morrisoni) flagellaris CklL, nor 

 is the fourth joint longer than the fifth ; and while the mesoscutum 

 is colored as in flagellaris, there is no yellow on the enclosure, 

 the insect is much smaller, the coxae are black behind, and tergites 

 2 and 3 have interrupted or very much narrowed bands. It is 

 much smaller than N. crazvfordi Ckll., and further differs in the 

 much narrowed or medially interrupted bands on tergites 2 and 

 3, the propodeum black with red areas sometimes enclosing small 

 yellow spots on each side of the posterior face but these not en- 

 croaching on enclosure, the flagellum wholly red above, the hind 

 femora with little or no black, the third submarginal cell not so 

 strongly angled on outer margin, etc. From A'', elrodi Ckll., 

 and A^. obliterata Cresson, the presence of yellow marks on 

 tergite i and numerous other differences are diagnostic. From 

 A'^. rhodoxantha Ckll. and A^. dilucida Cresson, it differs also in 

 the longer third antennal joint, the lack of a complete band on 

 tergite i, the largely yellow venter, etc. Along with this Ute 

 creek female is a male collected in the same locality on the next 

 day, June 28, 1907, by H. S. Smith. This male is, almost without 

 the slightest doubt, that sex of A'", alpha, so is described below : 



d*. Length 8.5 mm. Black; clypeus, triangular lateral face marks 

 extending narrowly along orbits about to level of insertion of antennae, 

 orbits beneath, labrum, mandibles except tips, scape in front, lateral lines 

 on collar, tubercles, small rounded spot beneath on mesopleura, two spots 

 on mesoscutellum, complete bands on tergites 1-6 (that on tergite i being 

 narrow and notched on the wavy anterior margin medially, that on 2 

 broad but medially narrowed, those on 3-6 subuniformly broad and occu- 

 pying the entire tergite except the narrow black apical margins), rather 

 bright yellow. Flagellum dark red beneath, above with a black line, the 

 scape behind except the yellow apex, black, antennal joint 3 two-thirds as 

 long as 4. Head and thorax coarsely, closely and shallowly punctured. 

 Clypeus and supraclypeus with appressed silky white hair, the labrum, 

 cheeks, occiput and thorax with longer, thin, erect, white hair, becoming 

 dense and silvery on pectus. Legs red, the coxae behind, spots on trochan- 

 ters behind, areas on fiist four femora behind, and posterior face of hind 

 femora (except knees) with a large area on their anterior face, black. 

 Wings hyaline, darkened along apical margin, venation as in the 5- Apex 

 reddish, slightly but distinctly notched. 



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