AMERICAN HYMENOPTERA. 69 



nearly subquadrate, the sides broadly and deeply grooved, mesothorax and 

 scutellum delicately punctured, a finely impressed longitudinal line on each 

 side over tegulee; metathorax smooth shining, impressed above at base; tegulse 

 pale testaceous; wings whitish-hyaline, nervures and stigma pale yellow, mar- 

 ginal cell as long as first submarginal, broadly truncated at tip, second sub- 

 marginal half the length of the first and narrowed to marginal; legs slender, 

 piceous, thinly clothed with white pubescence, anterior tibiae in front and all 

 the tarsi pale; abdomen oblong-ovate, depressed, black, the depressed apical 

 margins of the segments very pale, almost whitish, and more or less thinly 

 fringed with white pubescence, more obvious on apical segments, extreme 

 lateral margin of segments and the terminal segment testaceous. Length 

 .32 inch. 



Hah. — Colorado, (Ridings, Morrison). Two specimens. 



Perdita. zebrata. — $. — Very much like albipennis Cress., but smaller; 

 head and thorax blue or greenish blue, thinly clothed with pale pubescence; 

 a deep longitudinal groove on anterior orbits, more conspicuous than in albi- 

 pennis ; sides of face narrowed above, clypeus, two dots above, sometimes con- 

 fluent, occasionally an irregular transverse line on front above antennce, labrum, 

 mandibles except tijis, scape beneath, interrupted band on prothorax.-tubercles 

 and tegulse white or yellow ; sometimes the clypeus has two or more black dots ; 

 flagellum pale testaceous, brown above; thorax smooth and shining; wings 

 whitish-hyaline, nervures and stigma white or yellowish, neuration as in 

 hyalina ; legs yellow the two anterior pairs more or less black behind, posterior 

 femora above and their tibiae except base, black, tarsi varied with fuscous; 

 abdomen oblong-ovate, flat, shining, yellow, with more or less broad black or 

 brown band at apex of each segment above; in well marked specimens these 

 bands bend obliquely downwards on base of the following segment; the first 

 segment being black or brown with a yellowish band on the disk; apical seg- 

 ments frinsjed with pale hairs; venter yellow. Length .25 inch. 



Var. — Four anterior legs entirely yellow; abdomen yellow with narrow 

 blackish band at apex of segments 1 — 4, ending laterally in a dot which is 

 sometimes separated from the band. 



Hah. — Colorado, (Ridings, Morrison). Seven specimens. This 

 species is quite variable in its markings and specimens will doubtless 

 be found with the abdomen entirely yellow. 



Mr. Frederick Smith, to whom specimens were sent, refers this 

 species to Nomioules Schenck. 



Perrtita afiiiii!^. — 9- — Form of zebrata; head and thorax blue or green- 

 ish-blue thinly clothed with pale pubescence; sides of face, narrowed above, 

 clypeus except sometimes two or more black points, occasionally a spot or two 

 above clypeus, base of mandibles, scape beneath, a spot on each side of pro- 

 thorax, tubercles and tegulae pale yellow; flagellum pale testaceous beneath; 

 wings as in zebrata; legs black with {)ale pubescence, the knees, and the four 

 anterior tibiae in front yellowish; abdomen black, shining, a yellowish band 

 on segments 1 — 4, interrupted on the disk and more or less dilated and oblique 

 on the sides; fifth segment immaculate and fringed with pale pubescence; 

 apical segment testaceous; generally, the spot on each side of fourth segment 

 does not reach the lateral margin. Length .20 — .25 inch. 



