154 ' AMERICAN HYMENOPTERA. 



Iji my key to Perdlta this runs down to 68, and agrees with albo- 

 rittata in the hairy clypeus, etc., but differs in the color of the legs, 

 etc. 



(IS.) Diadasia riiiconis n. sp. J . — Length 12 mm., anterior wing 9 mm. 

 Black, the pubescence pale ochreous ; face nearly square, covered with short, 

 whitish pubescence, more or less failing on lower part of clypeus, though dense 

 on lahruni ; occiput and cheeks also densely hairy, the occipital hairs more or 

 less ochiaceous; vertex shining; clypeus shining, with very large punctures and 

 numerous small ones intermixed ; mandibles without any light color; antennae 

 short, flagcUum rufescent beneath, first joint of flagellum slightly longer than 

 second and third together, second very short; maxillary palpi 6-joiiited, second 

 longest, then third ; fifth and sixth together not so long as fourth. Thorax 

 densely covered with short, pale, ochraceous pubescence, the color becoming 

 brighter on scutellum, and pale mouse-gray on pleura; disc of metathorax bare, 

 dullish, enclosure bounded by an impressed line; tegulas black, their basal half 

 pubescent. Wings smoky hyaline, nervures piceous. marginal cell with an ob- 

 scure, suffused brownish streak, starting from the stigma; second submarginal 

 cell very short. Legs black, with fairly abundant whitish or very pale ochra- 

 ceous pubescence; small joints of the four hind tarsi rufescent; scopa of hind 

 legs abundant, pale ochraceous, conspicuously plumose; tarsi with very dark 

 rufous hairs on inner side, those on basal joint of hind tarsi glittering with a 

 coppery lustre. Abdomen broad, black with broad bands of appressed, short, 

 pale ochraceous pubescence ; the first segment pubescent all over, the hairs erect, 

 though short toward base; the bands, which are apical, are on segments 2-4 

 roundly excavated on each side above, so as to be much narrowed at these points; 

 the fifth segment is covered with similar pubescence, thinner and with naked 

 dots toward the base ; the extreme apex and the margins of the ventral seg- 

 ments are clothed with dark fuscous hairs. 



Hab. — Rincon, New Mex., three at flowers of ChUopsu saligtia, 

 July 5, 1896. One had previously visited an asclepiad, as shown 

 bv the pollen masses adherent to the legs. 



I had taken this for a Synhalonia, but Mr. Fox wrote me that it 

 was a Diadada, and a subsequent examination of the moutli-parts 

 showed me that he was unquestionably correct. 



1,19.) Poilaliriiis californiciis (Cresson) % . — Length about 13 mm., an- 

 terior wing 9 mm. Head, thorax and first segment of abdomen covered with 

 fulvous pubescence, nowhere mixed with black, dense, except on clypeus and 

 middle of dorsulum, where it is sparse ; on the cheeks and underside of thorax 

 the pubescence becomes dirty whitish. Head broad, face nearly square; clypeus, 

 except a black spot on each lateral margin, a supraclypeal transverse band, lateral 

 face-marks shaped something like an Emnrgimda-shiiW seen from the side, but the 

 ends more produced ; labrum, except two large black spots at upper corners, and 

 the narrow apical margin (as also of the clypeus) and mandibles without, except 

 extreme margins, base and apex, bright lemon-yellow ; clypeus minutely granular 

 or tessellate, with tolerably close punctures: labrum shiny, subconfluently punc- 

 tured; vertex sparsely punctured; antennae reaching a little beyond tegulae. 



