AMERICAN HYMENOPTERA. 213 



Xyloeopa snbvarescens. — 9. — Head black tinged with blue, and with 

 a slight tinge of green on middle of face, clothed with white pubescence, which 

 is rather dense on cheeks and occiput, thin and slightly mixed with black 

 on the face; antennae slender, castaneous, flagellum black above; thorax blue 

 laterally, lieneath and posteriorly, clothed with whitish pubescence, mesothorax 

 and scutellum submetallic olive-green, changing to purple on the disk, clothed 

 with a yellowish puliescence, wanting on the smooth, inipunctured disk ; tegulffl 

 fulvo-testaceous; wings yellowish-hyaline, nervures honey-yellow; legs more 

 or less varied with shades of brown, clothed with whitish or pale oehraceous 

 pul)escence, that on tarsi beneath rufo-fuscous; abdomen strongly tinged with 

 green, clothed with an appressed pale pubescence, yellowish on basal segments 

 and more dense and white on apical margin of the segments, a narrow smooth 

 line down the middle of the segments, which has sometimes a purplish tinge; 

 anal fimbria blackish, tipped with ferruginous ; venter blue-green, clothed with 

 white pubescence, that on two apical segments black. Length .55 inch. 



'^ . — The green color on thorax and abdomen more brilliant, the pubescence 

 more decidedly yellow and more dense ; sides of face, clypeus, spot above, 

 labrum, spot or line on mandibles, scape beneath, and sometimes the basal 

 joints of flagellum beneath, dull yellowish; sometimes there are two black 

 spots on clypeus towards base; cheeks with long white pubescence; otherwise 

 very much like the J, except the narrower face and larger eyes. Length 

 .50 — .55 inch. 



Hah. — Mexico, (Sumichrast). Four specimens. 



Centris inont'ezunia. — 9- — Black; head and thorax with short, dense 

 oehraceous pubescence, paler on cheeks and thorax beneath, that on head, 

 thorax above and on sides tipped with black ; clypeus concave, a prominence 

 on each side at base, the apical margin slightly recurved, sharp and truncate; 

 sides of face narrowly, an interrupted band on clypeus, labrum except base, 

 and mandibles except tips, yellow; flagellum testaceous beneath; wings dark 

 fuscous, paler on apical margins; legs with pale pubescence, that on the four 

 posterior tibias and tarsi fulvous, long and dense on posterior pair, that on base 

 of intermediate tarsi short fuscous and fringed behind with fulvous; abdomen 

 fulvous, shining, first segment stained at base with brown, and thinly clothed 

 with a pale pubescence more or less tipped with black, that on apical segments 

 fulvous. Length .80 inch. 



'J,. — The yellow band on clypeus broad and entire; posterior femora very 

 much swollen, their tibiae rather more robust than in 9 and fringed behind 

 with fulvous pubescence, as is also the basal joint of their tarsi; abdomen 

 narrower and more convex and more thickly pubescent at base and apex. 

 Length .70 inch. 



Hah. — Mexico, (Sumichrast). Two specimens. 



Centris totoiiaca. — 9- — Small, black; head and thorax thickly clothed 

 with a whitish pubescence, that on vertex black, and that on thorax above 

 oehraceous; clypeus prominent, depressed medially, two confluent spots on 

 anterior margin, labrum and mandibles except tips yellow; flagellum dull 

 testaceous beneath; tegulae fulvous; wings hyaline; legs brown, the two pos- 

 terior pair more or less varied with fulvous, posterior femora slender, their 

 tibiae with long yellow pubescence, that on their tarsi black; abdomen fulvous. 



