78 CHARLES ROBERTSON. 



1. Oxybelus 4-iiotatiis Say. 



0. -i-notatus Say, Lout's Second Expedition, 338. 

 0. impatiens Sm., B. M. Cat Hym., Pt. IV, 390. 

 0. interruptus Cress., Proc. Eut. Soc. Phil, iv, 475. 

 0. Brodiei Prov., Faun. Ent. Can. ii, 811. 



9. — Closely and finely punctured. Clypeal process prominent; prothorax 

 carinate, scutellum with a median longitudinal carina ; postscutellum short, more 

 or less carinate. Squama small, short; spine short, truncate or rounded at tip; 

 base of metathorax with few reticulations on each side of spine. Abdomen 

 smooth and shining, closely and finely punctured. Black ; pubescence yellowish 

 on vertex and mesothorax, silvery on face. Spot on tubercles, sometimes wanting, 

 spot on tegulse and inner border of squama, white. Mandibles black, rufoi)iceous 

 towards tip. Antennje black, flagellum testaceous beneath; wing scales brown- 

 ish. Abdomen : segments 1-4 with a narrow white line on each side, the lines more 

 approximate on 3 and 4; 5th segment has a narrow fascia either continuous or 

 interrupted, or is entirely black. Legs black ; anterior tibise within, their tarsi, 

 and tips of other tarsi, dull honey-yellow ; middle and posterior tibise sometimes 

 with a white spot at base exteriorly. Wings whitish or yellowish hyaline, ner- 

 vures dull te.staceous or honey yellow. 



'^.—Smaller, a little rougher and more coarsely ])uuctured; spine narrower 

 and more pointed ; squama small; abdomen without lateral spines. Mandibles 

 black; anterior tibife and tarsi in front white or honey-yellow; middle tibise 

 from base towards tip exteriorly, and posterior tibise at base exteriorly, white; 

 abdomen 4-10 spotted, the spots growing smaller towards apex. 



Var. a. — Two spots on prothorax, anterior and middle femora at tips beneath, 

 white. Legs inclining to dull ferruginous. 



Var. montanus. — 9 . Appears a little larger, more pubescent. Two spots on 

 ]>rothorax, sometimes wanting, tubercles, spots on squamse sometimes connected 

 I)y a line across post.scutellum, white. Abdominal spots broader, more approxi- 

 mate, forming continuous bands on 4th and 5th .segments. Legs inclining to dull 

 ferruginous ; anterior tibipe and all tarsi more honey-yellow, the middle tibije 

 sometimes honey yellow in front; middle and posterior tibite with more white 

 at base exteriorly, on the former sometimes extending to tip. Wings more yel- 

 low, nervures honey yellow. 



%. — Abdomen 8-10 spotted ; the ornaments more yellow and more extensive 

 than in the typical form. 



Var. a.— Abdomen 12-spotted, continuous fascia on 5th segment, hind tibiie 

 yellow to tip, tarsi honey-yellow. Length 9. 5.5-8 mm.; "^ , 4-7 mm. 



Canada, United States. Forty-seven females, sixty-two males 

 (coll. Am. Ent. Soc. and C. R.). 



A very common and variable species. Specimens from Montana 

 show the richest livery, all the ornaments being present and widely 

 extended. In 0. emarginatus, also, Montana specimens show the 

 same tendency. 



I have taken it from May 9th to August 9th on flowers of Zizia, 

 Heracleum, Pastinaca and Cicuta (Umbellifera?). 



