NORTH AMERICAN HYMENOPTERA. 79 



2. Oxybelus similis Cress. 



0. simiiis Cress., Proc. Eut. Soc. Phil, iv, 476. 

 9 • — Head and thorax rough, with rather coarse and dose punctures. Clypeal 

 process prominent; prothorax carinate ; scutellum with a tine longitudinal 

 carina; postscutellum not carinate, strongly produced and rounded behind; 

 squama rising from the side of the base of postscutellum, small, short and strongly 

 curved. Spine broad, parallel, truncate ; base of metathorax finely striated on 

 the sides ; below spine, on the hinder plate, the median space is arrow shaped, 

 terminating below in a smooth depression, which is long pointed towards inser- 

 tion of abdomen. Abdomen with the segments densely and finely punctured at 

 base, more coarsely and sparsely towards apical margin, which is smooth and 

 shining. 



Insect black. Pubescence rather long and yellowish on vertex and mesothorai;, 

 silvery on face. Mandibles, except tips, rufopiceous ; flagellum piceous, testaceous 

 beneath ; wing scales honey-yellow. Abdomen : segments 1-4 with narrow lines 

 on each side dilated towards the disc and almost meeting; 5th segment with two 

 approximate dots on middle white. Legs black, anterior tibise and tarsi, and all 

 tarsi at tips dull houey-yellow. Wings hyaline. Length 6.5 mm. 



Colorado. One female, the type specimen (coll. Am. Ent. Soc). 



Resembles 4-notatus, but is more coarsely punctured, the meta- 

 thorax is less rugous and the postscutellum has a different form. 

 Differs also in the ornamentation of abdomen and in the color of 

 tegula?. 



3. 0.vybelu»« siibtilaf us n. sp 



0. mucronatus Pack, (nee Fabr.), Proc. Ent. Soc. Phil, vi, 436. 



9- — Head and thorax densely and very coarsely punctured. Clypeal process 

 prominent; prothorax punctured, hardly carinate or angular on the sides; scu- 

 tellum and postscutellum with a median longitudinal carina; squama rather 

 small and short pointed; spine tapering to a sharp point, channeled above at 

 base. Base of metathorax rough, with large polygonal reticulations. Median 

 space below spine with coarse reticulations above, terminating below in a smooth 

 depression; lateral faces with coarse reticulations, punctured. Abdomen convex, 

 smooth and shining, very coarsely and rather sparsely punctured, with a deep 

 and narrow longitudinal channel at base, segments depressed on apical margin, 

 strongly constricted between the segments. Black ; pubescence thin and white, 

 dense and silvery on face. Tubercles, spot on tegulse, spot on inner margin of 

 squama, whitish. Mandibles black, with a tinge of rufous in middle. Antennae 

 black, paler towards tip. Wing scales pale testaceous; squama whitish. Ab- 

 domen : segments 1-4 with an elongated whitish spot on each side. Leys black, 

 anterior and middle femora at tijis beneath, all tibiae at base exteriorly extending 

 more or less towards tip, whitish. Tarsi brownish: wings hyaline, fu.scous to- 

 wards tip in front, nervures testaceous. 



Var. 9-— Difl^ers in the following: two spots on prothorax, and postscutellum 

 yellowish. Abdomen : 1st segment with a large spot on each side, 2d with two 

 long spots pointed and almost meeting on disc, 3, 4 and 5 with a broad continuous 

 Iwnd, yellowi.sh. Anterior and middle tibiae exteriorly and anterior tarsi yellow 

 ferruginous (Colorado). 



