226 p. CAMERON. 



hook is black and is a little longer tlian the joint; the middle femora become 

 gradually widened below from the end to the apex of the basal fourth, where it 

 becomes abruptly narrowed and is there hollowed above in front. 



Oslar, Phoenix, Arizona ; October 4th. 



This species is not unlike 0. approximatun Cam. ; the % in that 

 species has the middle femora of normal form. It is not a typical 

 Ancisirocerns, there being hardly a transverse ridge on the first 

 abdominal segment, the sole difference being that the basal slope 

 is smooth, the roughness commencing at its top. The form of the 

 first abdominal segment is as in Nortonia. 



PterochiluN 5-faNciatus Say. 

 This species is in the collection from Berkeley, Colorado, and 

 Oslar, S. W. Colorado. One specimen is 18, the other 14 mm. long. 

 The size and shape of the black markings on the basal two abdomi- 

 nal segments vary ; in one it is shaped like an hour-glass, not con- 

 tinued to the outer edges of the segment at the apex ; in another 

 there is a triangle in the middle at the base, the apex of the triangle 

 being at the middle of the segment; from there it is continued 

 broadly to the outer edges of the segment. There is a shallow, 

 semi-circular incision on the apex of the clypeus ; the outer edges 

 forming blunt teeth. In the smaller example there is a yellow fas- 

 cia on the top of the red cl3'peus, the line on the lower inner orbits 

 being also yellow. Basal joint of flagellum red, the other joints 

 being brownish-red below. Palpal hairs long, rufous, sparse. Apex 

 of postscutellum transverse, the base broadly rounded. 



^Pterochilii!"* inaculifrons sp. nov. 



Black ; red are : a large triangular mark on the front, its base united above by 

 a transverse line to a broader one on the eye incision, the junction being above 

 the incision ; clypeus, mandibles, a broad line on the outer eye orbits, the pro- 

 thorax, except the basal slope, two marks on the centre of the scutellum, broad- 

 est at the base, a line on either side of the black central part of the metanotum, 

 the metapleuraj and two large marks on either side of the black central part of 

 the basal tvvo abdominal segments. Yellow are: a large mark, longer than wide, 

 transverse above, rounded below; a triangular mark on the sides of scutellum, 

 the apex at the base; postscutellum, the sides of metanotum broadly, and the 

 apices of the abdominal segments (the line on the first is dilated backwards 

 laterally, broadly and roundly) and a mark inside the red mark on the second 

 segment, bright lemon-yellow. Legs red, the coxai marked behind with black. 

 Wings hyaline, the apex largely sufiused with fuscous. Length (total) 14 mm. 9- 



Clypeus strongly punctured, le.ss strongly on the top, where it is bioadly 

 rounded; it becomes gradually roundly narrowed from the eyes; the ape.\ nar- 

 row, transverse. Apical two teeth of mandibles weaker than the basal two. 

 Front and vertex strongly and closely punctured ; there is a broad, longitudinal 



